Slitherine

Is it and how much concept of series contributed to variety of units in players core?

It is important to note that variety of units within the same class is not necessary applicable on not using best equipment available in certain moment (having all Panzer IV of the same type when Panther is available is not variety) but on general variety of units of different type within the same class.

I see concept of series as concept that allowed more frequent upgrades of units which availability was supported by discount in upgrade price for equipment in the same series but I do not see concept of series as crucial factor creditable for variety of units within the same class.

Opinions?

I'm not sure if I am addressing your point exactly, but I will try:

I very much like the different series of unit types within a class (Class="tank", Series= "Pz.III," Pz.IV," "Panther," etc.)

It adds much to game play to have to weight and balance the different characteristics of each, and foreign captures, when deploying and fighting. You are correct that with more series, the more frequent upgrades give the player things to think about and analyze. It also makes you deploy a more historically accurate "core" with heavy and medium/light tank groupings so as to create balance.

In the past, I would upgrade to the "best available" across the line as much as possible. But I now play on the 'Rommel' setting so I can not afford to do that, and work harder to integrate more varied units/Series into my core.

A reduction in prestige an maps will help allot, as I always use a few tanks that are not top of the line to save on prestige.

Series concept is taken for granted...

The fact one can upgrade equipment at discount price within the same series is not the reason why sometimes best equipment available that comes from other series is not easily available. The reason for this is ...lack of prestige.

If we remove series concept from the game, upgrades are not going to be more easily available. On the contrary it would require to pay full price for every upgrade thus making best equipment available at certain moment even more harder to acquire (with assumption prestige allotment had stayed the same).

If all types of equipment within the same class are placed in the same series, upgrades would be more accessible (with assumption prestige allotment had stayed the same) which leads us to conclusion that series concept is the one that stimulates upgrades by offseting influence of prestige. Series concept is not the one that restricts use of best equipment available, on the contrary in certain occasions it even stimulates it.

I don't quite understand the OP's question. Basically, are you asking whether having the series like the PzIII and PzIV encourages players to get those medium tanks as opposed to buying heavy tanks? And what do you mean by unit variety? Are you asking whether about having say a PzIVG vs a PzIVH vs a PzIVJ, or are you asking about something more broad like a PzIV vs a PzV?

I have thought quite a bit about the equipment file for units, at least when it comes to all the DLCs. This is honestly a topic that can't be covered easily in just a few sentences. I created a series of equipment files that I think encourages the player to field a variety of units, each with their strengths and weaknesses. I tried to make it so that there isn't an obvious "best" unit in a category. If you're interested in my philosophy, you can download the manual I wrote for my mod and read the contents.

uran21 wrote: If all types of equipment within the same class are placed in the same series, upgrades would be more accessible (with assumption prestige allotment had stayed the same) which leads us to conclusion that series concept is the one that stimulates upgrades by offseting influence of prestige. Series concept is not the one that restricts use of best equipment available, on the contrary in certain occasions it even stimulates it.

The battle history - experience, hero bonuses - also plays a big role in whether units are disbanded, upgraded, or left intact.

E.g. - a foreign capture like a Souma that is used a long time, earns 300 exp and a nice bonus, I would "upgrade" to a Tiger later or perhaps a IV when needed instead of disbanding. Likewise, by my-'43, a Pz.IV with lots of experience and heroes can stay a Pz.IV.

The concept that seems to be missing in the Series concept is that of the human capital. Disbanding a very experienced unit to purchase a green higher-series one just feels wrong. The men wouldn't just "disappear." I wonder if there's a way to upgrade between series that reflects this reality. Raising a brand-new Panther unit, for example, is clearly a much more difficult task than simply issuing an existing unit Panthers in the real world.

I think the low cost of series upgrades reflects this well. Sure, sometimes it's a bit odd because series upgrades were in fact entirely new equipment built from the ground up, so really no different than upgrading to a different type. However sometimes they were just depot modifications to existing equipment (some StuG models, some Panzer models, for example). Perhaps if Series upgrades were more expensive it would also help achieve the goal you are looking for.

In my experience, in the basic game the prestige levels are VERY generous. They pose no limits on really always having the best available - that restriction is the time of availability and not whether it's a series upgrade or new equipment type.

Variety of units in players core has two levels. Grand level deals with question of representation of all purchasable classes in players core. Other level deals with question of representation of different unit types within the same class. Different unit types by definition do not recognize various series.

So sequence of PzIIIG - PzIIIH - PzIIIJ is equally varied as PzIIIJ/1 - PzIVG - PzIVF2 which in turn is equally varied as PzIIIM - PzIVH - Panther A.

Subject of the topic is more narrow though. It deals with question is it and how series concept contributed to the variety of unit types of the same class in the players core.

Hypothesis laid down is that concept of series is not a crucial factor creditable for variety of units within the same class. Of course I am ready to change opinion if someone provides strong enough arguments against it. But on the other side I would like to hear more arguments supporting the hypothesis, if any.

To contribute more on supporting hypothesis, another example. Prior to availability of Panzer IV with long barrel, PzIII and PzIV (short barrel) tanks have complementary roles supported with unit statistics that give each tank advantage in different field thus making use of both desirable. They are placed in different series thus making less likely upgrade switching between the two. But if we remove concept of series using both tanks will still remain desirable because it is concept of complementary roles which is creditable for variety in this case.

Hypothesis laid down is that concept of series is not a crucial factor creditable for variety of units within the same class. Of course I am ready to change opinion if someone provides strong enough arguments against it. But on the other side I would like to hear more arguments supporting the hypothesis, if any.

I'd have to agree. I don't think series upgrade has much impact on weather you have a variety of tanks. For me the most important reasons to keep a variety of units in my core, are the attributes and differences of the units themselves, the roles they fulfill, and the requirements that the battlefield or the enemy dictates. PzIII and Pz IV is the obvious example as you mention. A core with both types is more versatile than one with all Pz III's so i keep both in my core. Upgrade potential is a minor consideration in comparison and i don't see how it encourages variation. The line is blurred somewhat in 43/44 though where the primary role of the tank becomes its ability to survive and destroy other tanks. Even here there is subtle differences between the Tigers and Panthers but there's little incentive for keeping your Pz IV's if you can afford to upgrade to the former. Pz III N is different story though (because it performs a different role). Variety is highlighted and encouraged in the DLC's with the captured equipment. The soviet and French tanks have a different flavour and there handy to have around because of this, maybe there were a few to many though. For a while it looked like i had defected to the red army and my tanks might start shooting at each other in confusion .
The other obvious factor is prestige. If I'm strapped for cash like i am in my modded DLC my core is going to look a lot more varied than it would if i had 20 000 + prestige stored in the bank.

If we remove series concept from the game, upgrades are not going to be more easily available. On the contrary it would require to pay full price for every upgrade thus making best equipment available at certain moment even more harder to acquire (with assumption prestige allotment had stayed the same).

I wouldn't like to see it removed from the game as it makes historical sense to me but I think the in family upgrades could be a little more expensive. Going from Stug III F to Stug III G costs about 20 bucks, less than 10% of the unit price.

uran21 wrote: So sequence of PzIIIG - PzIIIH - PzIIIJ is equally varied as PzIIIJ/1 - PzIVG - PzIVF2 which in turn is equally varied as PzIIIM - PzIVH - Panther A.

I don't understand what the designer goal here is. Is it to encourage players to field a number of different units in a class, no matter what these units are? So PzIIIG - PzIIIH - PzIIIJ is as acceptably diverse as PzIIIM - PzIVH - Panther A? I think it's really difficult considering there are about 20 different tanks for the Germans alone. I can't imagine how a designer could design stats to make every single tank unique and desirable without a massive reworking of the prestige and core systems. Having there be a difference between the PzIII vs PzIV vs Panther vs Tiger I vs Tiger II is I think a more realistic goal, with some small variations therein (like the PzIIIN being an excellent urban warfare anti-soft unit).

If taken literally, yes, all of those sequences are equally as varied since each has 3 different units. But I would argue those listed sequences are not equally varied. The first series are all Panzer IIIs with the same 50mm guns, just each unit is more progressively well-armored with some minor differences in fuel ammo. The second series has more variety, the PzIVG and PzIVF/2 have much better SA than the Pz IIIJ/1, not to mention there are significant differences in armor. The last series is the most varied, since the PzIIIM is a dedicated hard unit killer (and not very good by 1943 standards), while the PzIVH has good SA and decent HA, and the Panther A is fast, extremely good against other 1943 tanks, and has decent SA too albeit at a higher cost. These 3 sequences are very different for gameplay purposes.

I agree that in some ways series is detrimental to unit diversity. In Afrika for instance, since 1942 comes along pretty fast, the PzIV is a much better choice than the PzIII since you can upgrade to the long-barreled PzIV relatively quickly in series for a cheap price, while the PzIII's stats become lackluster just 5-6 scenarios in. It might increase diversity if there were no series upgrade, but...

Removing series from all units isn't necessarily a good way to encourage unit diversity either. A savvy player will simply identify points in time when it's wise to make a mass upgrade to skip certain intermediate units all together. For instance, in GC42 in the stock eqp file the Panzer IVF/2 (cost 412) is available in scenario 1 but the Panzer IVG (cost 466) is available in scenario 2. If you had to pay full price for every upgrade, who would ever upgrade to the Panzer IVF/2 in scenario 1 when you can simply wait one scenario and upgrade to the Panzer IVG? Without series, it might also further encourage the practice of disbanding a unit before buying another.

Edit: another example, consider the Panther A vs Panther D vs Panther G. Without a series, if you have a Panther A, there's no reason to pay 655 prestige for the Panther D's 20 more fuel and minor AA capability. Same thing for another 674 prestige to gain 1 GD and 1 AD for the Panther G. On the other hand, with a series, there's little reason to NOT upgrade for a tiny, tiny cost to get those extra benefits. So pick your poison in the case of the Panther tanks. To encourage all Panthers to be viable, you'd need to completely redo their prestige costs, and then you'd need to completely rethink the prestige of other tanks and the prestige levels in scenarios to balance this.

I like the series concept since it allows a player to maintain immersion by having cheap upgrades sprinkled throughout the game as opposed to having to research all the units/scenarios beforehand to identify optimal points to upgrade.

I wouldn't like to see it removed from the game as it makes historical sense to me but I think the in family upgrades could be a little more expensive. Going from Stug III F to Stug III G costs about 20 bucks, less than 10% of the unit price.

I agree, there are certain points where it becomes clearly a nobrainer to make some upgrades in a series. In my experience working with the equipment file, it is hard enough to design a eqp file just to encourage diversity between say the StuG III - Marder II - Marder III much less diversity between all the submodels of each of those series. The only way I could see making all the submodels be worthwhile would be to completely redo all the prestige levels, and that involves changing all the prestige values in the GC too.

It might be interesting if there were some way to encourage a player to use more "obsolete" equipment, like a PzIIIG when a PzIIIH is available, but this is not possible with a static equipment file. If you had a dynamic equipment file, where the cost of new units is extremely high at first but then comes down in price progressively, or if each unit of the same type gets progressively more expensive (ex. the first Panther A cost 500 but the second cost 1000), then you could probably accomplish this. There's no real way to do this with the current game engine though, short of having a customized equipment file for every scenario, which is a huge amount of work.

The idea behind series was to delay people upgrading to the latest and greatest equipment because they could get something maybe a little bit worse, but still viable and much cheaper. For example, in PG people jumped to FW190 as soon as it became available. Series were supposed to induce people to upgrade alone the Bf109 line much longer, and maybe upgrade to FW190 unit by unit, as more funds become available.

There are two problems with this approach.

First, historical equipment does not have a lot of useful series we could benefit from. Thus, in tank realm, PzI and II lose their viability very quickly, and, as was noted above, PzIII and IV are different enough, so that we cannot really consider them direct competitors.

Second, and this is probably a more important problem, in PzC it is usually cheaper to have a stronger unit in the core even if it is more expensive to buy. Replacements will quickly eat up all funds saved on buying a cheaper unit.

Combined result of these two issues is probably that the series concept does not play an important role in the game.

It might be interesting if there were some way to encourage a player to use more "obsolete" equipment, like a PzIIIG when a PzIIIH is available, but this is not possible with a static equipment file. If you had a dynamic equipment file, where the cost of new units is extremely high at first but then comes down in price progressively

Are you sure this isn't possible with one standard equipment file. I though it might be possible to have 2 Pz IV G tanks in the same E file but have them phase in and out at different times so that only one is available on the purchase screen at any given time. The initial Pz IVG becomes available at the usual date but has its availability end in mid 44 when the King tiger appears. At this point the second Pz IVG becomes available at a considerably lower price. Thus it has become a cheaper and more viable option when it has become obsolescent.
It would take a lot of work but could be doable unless you cannot have 2 units in the e file with the same name.

Rudankort wrote:The idea behind series was to delay people upgrading to the latest and greatest equipment because they could get something maybe a little bit worse, but still viable and much cheaper. For example, in PG people jumped to FW190 as soon as it became available. Series were supposed to induce people to upgrade alone the Bf109 line much longer, and maybe upgrade to FW190 unit by unit, as more funds become available.

Okay, this is going to be another long post, so bear with me on this. When playing the GCs, I noticed and then thought about exactly this problem for a very long time, and I think I finally found an approach to deal with this by modifying both the eqp file and the gamerules.pzdat. The following is my method of alleviating the problem you described, using my 1943 eqp file and gamerules.

UpgradeExpPenalty = 225 (unmodded = 0)

Units Stats:
Bf 109F cost = 449 ammo = 5 fuel = 75 INI = 11 AA = 13 AD = 21 GD = 21
Bf 109G cost = 480 ammo = 5 fuel = 52 INI = 10 AA = 15 AD = 20 GD = 20
Fw 190A cost = 633 ammo = 4 fuel = 50 INI = 11 AA = 18 AD = 21 GD = 21

Let's say you had a 400 exp Bf 109F at the start of 1943. Your choices are
1. Upgrade to the Bf 109G for 31 prestige, losing some fuel, 1 INI, and defenses for +2 attack at the cost of 31 prestige, but you keep all your experience.
2. Upgrade to the Fw 190A for 633 prestige, your resulting Fw 190A will have only 175 experience, but you do keep all your heroes.
3. Disband the Bf 109F to buy the Fw 190A for the cost of 184 total prestige but at the cost of all your experience
4. Keep the Bf 109F but buy a new Fw 190A to use alongside it.

For comparison:
400 exp Bf 109F INI = 15 AA = 17 AD = 25 GD = 25
400 exp Bf 109G INI = 14 AA = 19 AD = 24 GD = 24
400 exp Fw 190A INI = 15 AA = 22 AD = 25 GD = 25
175 exp Fw 190A INI = 12 AA = 19 AD = 22 GD = 22
0 exp Fw 190A INI = 11 AA = 18 AD = 21 GD = 21

Conclusions about the choices
Choice 1: 2 extra AA is almost certainly worth it despite the small loss of INI and GD
Choice 2: If you are swimming in prestige and have desirable heroes (especially INI heroes), this can be a good choice too. It'll take many scenarios and quite a few rounds of elite reinforcements before you can get back up to 400 exp, by which point the Fw 190A is clearly the best plane. But it'll certainly be expensive to get to this super unit.
Choice 3: This seems to be a very poor choice, because a green Fw 190A is much worse than a 400 exp Bf 109F, not to mention the huge amounts of elite reinforcements it'll cost to bring this unit up to 3-4 stars.
Choice 4: This is also a pretty good choice. From a metagaming standpoint, even keeping a veteran fighter in reserve is not a bad idea, for use in some missions like Prokorovhka where the AI's air opposition is particularly fierce and you get extra core slots. It is aso possible for the Red Air Force to shoot down a German fighter in 1943, so having a veteran in reserve could be very useful.

Since the player generally has several fighters, it probably makes the most sense to upgrade 1 or 2 Bf 109 out of series at a time to ensure that the rest of the fighters are veterans, since veteran fighters are much, much more powerful than green ones. So I think Choice 1, 2, and 4 are all viable. Choice 1 is the most prestige efficient, but Choice 2 is very good for someone who wants to spend prestige on this particular upgrade. Admittedly keeping the Bf 109F un-upgraded is not really a good choice, so I fail the diversity test in that regard. However, without changing the prestige system very significantly, I'm not sure how to make the Bf 109F as attractive as the Bf 109G.

It is a good idea for the player to have some Fw 190s in 1943 though, because certain Soviet fighters (Yak-3) are very tough, and also the Il-2 has very high AD that it is best to use Fw 190A to shoot them down quickly. But switching all fighters to Fw 190A once it is available is not necessarily the best choice, although if you have the prestige, there's no artificial limitation that forces the player to limit his upgrades.

I think it's fine to have some upgrades be a pretty obvious choice, as long as there's an opportunity for a unit to shine. The Bf 109F is available for all of 1941 and the Bf 109G only appears in GC42 scenario 5 (as opposed to scenario 2 unmodded, furthermore in GC42 the Bf 109F has ammo = 4 vs the Bf 109G ammo = 3), so there's plenty of time for the Bf 109F to shine in GC41 and GC42. I personally think my eqp file offers more choice than the unmodded eqp file, where there's no expupgrade penalty and the Fw 190A has AA = 20 vs Bf 109G with AA = 14, making the Fw 190A so much better that it's makes the most sense to upgrade all fighters to the Fw 190A ASAP. I'd be happy to hear any feedback that might improve my system too.

Second, and this is probably a more important problem, in PzC it is usually cheaper to have a stronger unit in the core even if it is more expensive to buy. Replacements will quickly eat up all funds saved on buying a cheaper unit.

I'd say that's the main problem and the only real solution, as done in eg. deductors awesome GC mod (hurry up with the new version mate! ) is to increase the price of the expensive tanks even more.

UpgradeExpPenalty is a strong measure, but during the original PzC beta it was very unpopular, and for this reason removed from the game.

soldier wrote:
Are you sure this isn't possible with one standard equipment file. I though it might be possible to have 2 Pz IV G tanks in the same E file but have them phase in and out at different times so that only one is available on the purchase screen at any given time. The initial Pz IVG becomes available at the usual date but has its availability end in mid 44 when the King tiger appears. At this point the second Pz IVG becomes available at a considerably lower price. Thus it has become a cheaper and more viable option when it has become obsolescent.

The following is flaw with this approach unless you can have the original PzIVG have an automatic reduction in price, which is impossible by having just 1 eqp file. Consider the following hypothetical example:

1942 Panzer IVG cost = 500
1943 Panzer IVG cost = 400
1942 Panzer IVH cost = 500

If you have the series concept, you can upgrade to both the Panzer IVH or the Panzer IVG for 0 cost. If you don't have the series concept, you can really confuse a player who sees "hey, I can upgrade my Panzer IVG to another Panzer IVG... for 400 prestige."

Rudankort wrote:UpgradeExpPenalty is a strong measure, but during the original PzC beta it was very unpopular, and for this reason removed from the game.

Yes, I'm not saying my approach is for everyone. I don't think you can have a single set of rules that appeals to everyone. In fact, the default gamerules.pzdat is probably the best for 95%+ of players and makes the most sense for a retail release. But if you want to play with, say, "advanced" rules, the upgradeexppenalty works beautifully to solve the exact problem you mentioned. So big thanks for including it as a modding option!

Uran21, I think you're mostly right, the series concept does not really promote having a diversity of units within, for example, the tank class, as most models will be upgraded at the latest series model a little extra cost. So a core would upgrade all Panzer III to the latest model as it is cheap and effective. Most players might have several different series in their core, but they will all probably be the latest model. But I think the series upgrade system still promotes not everyone upgrading all their tanks to Panzer IV F/2 when they come available, but the penalties could be a bit higher.

Maybe a little tweaking of the existing system would be enough to encourage players not to 'automatically' upgrade equipment when newer things become available.

When I upgrade my Panzer IV D, step by step, the amount of prestige you pay is just the difference between the old and the new purchasing price. Since there are virtually no trade-offs in performance, each upgrade is usually a no-brainer, and I think they are too cheap. But paying the full price for some bolted on armor that could be retrofitted in the field is too much, and will encourage people to only use certain cost-effective models which skip certain upgrades because the benefits are too expensive, and everybody will upgrade Panzer IV G's to Tigers instead of keeping the Panzer IV because upgrading it makes little sense if you have to wait longer to pay 486 prestige for HA+1, AA+1,INI +1, GD+2 and CD+1, instead of paying 703 for SA+1, HA+4, INI+3, GD+9, AD+5, and CD+2. So series upgrades should remain, but they could be tweaked a bit.

I've looked at the gamerules.pzdat, and there is a setting, 'Upgradecost', that determines how much percent of the new price you pay when upgrading outside a series. But, I've noticed this also influences the extra cost of upgrading within series. If I set it to double the price (200 instead of 100), than you also pay double the price difference when upgrading within series. Example, Panzer IV G to H, normally 20 prestige, now 40 prestige. And this I like, it seems like a good penalty and the player has to think more carefully about the cost effectiveness. It will hopefully promote using slightly older but still usuable equipment, and make upgrading still more attractive than purchasing newer models or upgrading to Tigers.

But the downside is that upgrading outside series becomes extremely expensive if left at 200. I think it's a good idea to pay a little extra when upgrading a Panzer III to a Tiger to transfer experience and heroes to a new unit. But doubling the cost is too much here, this could better be set at somewhere between 105-125. Couple that with increasing the experience loss when upgrading outside series like in deducters' mod. But I would like to be able to seperate the penalties when upgrading in series from upgrades outside them, for the cost as well and maybe even for the experience loss, as new but similar equipment often needs some familiarization (e.g. new gunsights, ballistics, maintenance procedures), but not as much as transferring outside series. Is it possible to add this as an extra variables? So you can have a regular 'Upgradecost' vs. 'UpgradecostSeries', and 'UpgradeExpPenalty' vs.'UpgradeExpPenaltySeries'.

I'm not sure of course, but I these two proposed mechanisms may promote using more varied equipment. I see deducter has used the time I needed to write this all up to post similar examples. I echo his worries that savvy players will skip upgrades, and only certain units will see a lot of use, while the intermediate steps get ignored.

ThvN wrote: I've looked at the gamerules.pzdat, and there is a setting, 'Upgradecost', that determines how much percent of the new price you pay when upgrading outside a series. But, I've noticed this also influences the extra cost of upgrading within series. If I set it to double the price (200 instead of 100), than you also pay double the price difference when upgrading within series. Example, Panzer IV G to H, normally 20 prestige, now 40 prestige. And this I like, it seems like a good penalty and the player has to think more carefully about the cost effectiveness. It will hopefully promote using slightly older but still usuable equipment, and make upgrading still more attractive than purchasing newer models or upgrading to Tigers.

I noticed this feature too, but I couldn't reasonably include it in my mod since I don't want it to cost say 2700 prestige to upgrade a Panzer III to a Tiger I. Upgrading to a new model should never cost than buying a new unit.

Is it possible to add this as an extra variables? So you can have a regular 'Upgradecost' vs. 'UpgradecostSeries', and 'UpgradeExpPenalty' vs.'UpgradeExpPenaltySeries'.

This would be the ideal method. Let there introduce a new variable that affects the cost of upgrading in a series besides a simple prestige difference between old model and new model!

Rudankort wrote:UpgradeExpPenalty is a strong measure, but during the original PzC beta it was very unpopular, and for this reason removed from the game.

And it has the defect of also being ahistorical - a unit doesn't forget how to fight because it has new equipment. But also the player, after investing so much time, effort, prestige building a unit would be annoyed at this; very understandable.

While it requires more programming work than just tweaking existing tables, what about availability limits? Is there a solid reason to not (eventually) go this route?

As things stand, the units seem well-balanced to reflect diversity and historical accuracy. Without having to "re-invent the wheel" by completely re-writing the equipment characteristics, prestige mechanics, etc., couldn't there just be absolute limits on the number of new units in a series available? This would have the virtue of also being historically accurate. And it could change over time. E.g., two panthers total in 1943, three in '44, etc. Likewise, slowly increasing availability of a FW190, etc. would serve to have the two fighters working in tandem.

Kamerer wrote: And it has the defect of also being ahistorical - a unit doesn't forget how to fight because it has new equipment. But also the player, after investing so much time, effort, prestige building a unit would be annoyed at this; very understandable.

I think an expupgrade penalty is more realistic, not less. Right now, you can upgrade a Pak 40 to a Elefant and mantain the same amount of experience. Or convert a Bf 110 to a Ju 87. Or retrain a 4-star infantry to paratroopers instantly. Don't these examples seem more unrealistic?

Historically even experienced crews need a period of rest, refit, and retraining to get used to new equipment. New equipment wasn't just issued in the field, infantry can't magically convert between infantry/combat engineers, and any other of examples like that. There's no way in PzC to model this, so I personally think under an "advanced rules" system it the lesser of sins to have an experience upgrade penalty.

As things stand, the units seem well-balanced to reflect diversity and historical accuracy. Without having to "re-invent the wheel" by completely re-writing the equipment characteristics, prestige mechanics, etc., couldn't there just be absolute limits on the number of new units in a series available? This would have the virtue of also being historically accurate. And it could change over time. E.g., two panthers total in 1943, three in '44, etc. Likewise, slowly increasing availability of a FW190, etc. would serve to have the two fighters working in tandem.

Limiting the number of certain units is also extremely unpopular. Anyway, if you design the correct equipment files/game rules, you can still encourage a diversity of choice without artificial limitations. In my mod, a player can still choose to buy as many Tigers as his prestige allows.