Slitherine

I really cannot seem to comprehend the supply mechanic in this game at all, and this isn't the first mission to annoy me regarding it.

As I understand it, as long as an enemy is surrounded by Zone of Control and/or impassable terrain, it will be encircled and out of supply and easy money.

I had this issue in the other encirclement mission in 1943, the one where you punch over the top of the map and behind the enemy - even with the 'screening' force of NPC Allied Germans up at the top of the map, the encirclement didn't trigger until I manually put units literally within a few hexes range of the enemy units.

And so it is proving again, with Margarethe - the briefing says to encircle the barracks - putting a unit next to them does encircle the barracks, but you get 1 shot because the barracks is 110 strength. But, even if I capture the two hexes next to it, I should surely surround it simply with two units blocking the north/south saliant (if the hexes are east/west), but this simply isn't the case at all.

If I move on, I can create huge encirclements of everything inside the battle zone, but behind me? No, that's somehow magically getting supply, from somewhere.

Am I misunderstanding the briefing here? Am I meant to basically encircle the spawning units instead of the barracks? It doesn't seem right to be dropping 4-5 units for an encirclement of the barracks (wide net to avoid being shot by them basically)?

So, I must be missing something and turn to the forums for help.

Spawns has nothing to do with supply system, they are scripted and nothing stops that as long as the script itself reaches the required situation. For this scenario (and every else scenario with units spawning in the middle of one) it is solely determined by the turn counter, happens when the designated turn comes. So you are supposed to encircle the units spawned and not the barracks themselves, telling from the strength they are given. It's quite possible that they don't have a way to disable the spawn zone if one of the "barracks" gets encircled, technical issue with the editor and scripts currently available, maybe.

btw, your understand towards the supply system has one missing point, that a Supply Hex also provides supply besides the map borders, only completely cutting off all possible routes to the borders AND Supply Hexes with unit ZOC and terrains impassable for vehicles would make units inside the pocket "Encircled".
Try Kiev in AO41 again if you didn't follow the objectives given in your last run, you can encircle the whole enemy body if you keep all the marked hexes occupied, no need to get close to the city or those sitting inside the line, because that map was designed specially for that action, every other routes to map borders (they don't have a supply hex inside) has been blocked by allies and terrain except the direction you are attacking.

Aha, I see, so the border hexes are free supply - which, I think, shouldn't be the case, as if you go that way, surely it's the realm of the rest of the Army Groups?

I figured it out eventually, and cleared the map quickly enough that the few that did spawn didn't bother me. It was just bugging me about the encirclements, but I got it done.

It’s definitely a flaw in supply mechanic. Infinity supply for a single supply hex. So a completely encirclement is needed all the way.
For me it’s ridiculous and OoB has far more complete supply mechanic with visible supply line.
But its understandable in PC2, just think how easy to totally cut off enemy fighting force with a bonus movement light unit.

I agree, OOB supply lines was superior, though, I didn't enjoy the game, personally.