If you want to understand where the army comes from, and some hints in how it should be used, it pays to go back to the source material. In this case, we have a Byzantine emperor who allegedly wrote an entire military manual:
https://en.wikipedia.org/wiki/Strategikon_of_Maurice
Here are the
key elements in my opinion:
1) Cavalry is the primary, decisive arm; Infantry exist mostly to occupy key terrain aka hills and engage after the enemy is weakened.
2) The Byzantines were less interested in destroying the opposing army completely, because weakening a foe on their border usually resulted in a more powerful neighbor taking their place. Their experiences with the Huns clearly informed a lot of their military doctrine. Better the devil you know than the one you don't.
3) As one of the only states around with a professional military infrastructure, the Byzantines could actually copy enemy military technology and make their own versions. Less effective than warriors who practiced those arts from birth, sure, but few other states could artisanally craft their own horse archers from scratch.
4) The culimination of all this was the Hybrid Lancer Horse Archer. These soldiers were trained to shoot the bow Hun style (forward, backwards, to the side, all while moving) and then switch to a short lance for an ordered charge once the enemy was disrupted. This was deadly against infantry. To defend against heavy cavalry, infantry naturally pack close together, but this makes them vulnerable to arrow volleys. To defend against arrows, infantry naturally spread out, but this makes them vulnerable to lancer charges. Against horse archers, the Byzantines switch to the lance and charge, rather than shoot it out with experts. Against dedicated lancers, the Byzantines were trained to act like horse archers and lure the lancer charge into a trap.
FoG2 kind of gets some of these things right, and some not so right. The lancer poa works great at trapping infantry in place to be shot, and pushing horse archers around with the charge. Against lancers, though, things fall apart. Hybrid lancers don't evade like other bow cavalry, so heavy western lancers can charge them no problem, and then win pretty easily. And if you bring the superior hybrid lancers, you're paying 8 extra points for a unit that they will charge anyway just to stop you from shooting. I've said elsewhere that I think hybrid lancers should have evasion capability, but not everyone agrees with me. *shrug* As it stands, there are ways to mimic the Byzantine lure strategy - either by keeping hybrid lancers at a far distance and hoping the superior enemy lancers move aggressively, or by using those Byzantine army lists that have large amounts of pure bow cavalry.
Army Composition and Unit Tips
I'll second a lot of what Snugglebunny said, and elaborate on a few other things. The major weakness of the Byzantines is that they pay a LOT for hybrid units that perform worse when facing pure units in their element. The key is to do your best to make those pure units operate outside of their element. Some examples:
- If you have a Middle Byzantine list with Skutatoi/Archer infantry that are hybrid bow/defensive spears, enemy 36 point defensive spears will beat down your 47 point Skutatoi/Archers; instead, make enemy infantry face your hybrid lancers. Infantry charging lancers are at a huge poa disadvantage, and have to deal with the lancer cohesion penalty. Most times they will pass the check and your lancers will bounce back. But the infantry will take damage and will be slowed down. If they don't want to charge, then they get to sit there and be calmly shot down by the hybrid units.
- Those same skutatoi/archers work wonders against lancer cavalry. Lancers hate charging spears and usually just have to sit there and trap them. But now they're facing a spear unit that can just calmly shoot them at close range for big damage over time.
Other general tips:
- Skutatoi/Archers love being on hills. The extra 25 poa helps in melee vs. basic spears, and the elevation allows for them to fire over skirmishers or vice versa. This plays into the primary role of Byzantine infantry to just hold the good ground.
- If you can, bring the Power Units. Some Byzantine armies have access to uber powerful units for their time period. The Byzantine 551AD list (Belisarius Army) has access to 72 point armored superior spears and 54 point superior spears. While few in number, these units can punch quite heavily in melee fights against most units. The Middle Byzantine lists (900-1000) have access to Klibanophoroi and Varangian Guards. These are horribly expensive units, but they have high morale and massive armor. They can act either as deterrents or sledgehammers in the right situation. Normally, most enemies want to immediately charge Byzantine units to stop the arrows, but the presence of power units makes that less appealing. The Klibs in particular are pretty fantastic as they allow the Byzantines to take an expensive advantage in cavalry fights, and if they get trapped in melee with spears, they are still very, VERY hard to kill. With high armor POA and Elite morale, I've rarely seen them drop cohesion, and they can be relied on to fight to the death in most cases. Of course, expensive power units exacerbate the point cost problems inherent in the Byzantine army, so be careful.
- Comitatensis units in the Early Byzantine list are over-priced for what they do. They cost as much as Imitation Legions, but have substantially less utility. The Auxilia Palatina that also carry the Darts POA are 6 points cheaper than their Impact Foot twin, so hopefully the Comitatensis will drop from 51 to 45 points soon. That should help the early list a bit with cost efficiency.
In summary, the Byzantines just aren't an easy list to use. They're not Medium Foot spam; they're not beefy heavy infantry; they're not cheap horse archers. They take more than a bit of practice to figure out. How do you handle rough ground? How do you prevent enemy units from engaging you before you're ready? Much like the Strategikon, you will need a specific strategy for each type of enemy you face.