I think the flak halftruck suffers from battlegroup HQ being weaker. If I had to rebalance the okw tiers a bit I’d put the stuka HT on Battlegroup, IR HT on Schwerer HQ and the 250 HT from Ostheer on the mechanized HQ. Stuka and HT would be a nice combo.
OKW design is around poor combined arms strategies, at least until midgame. Since most OKW units tend to be really good at one specific task, the only possible weakness to stop it from being stupid OP is a bad synergy between its units.
Because of that i disagree. WStuka must be locked behind a more risky and expensive tier, because it fights very effectively static gameplay, allied team weapons have almost no chance against it and in teamgames they can exploit their teammates pushing the frontlines meanwhile stukas deal with ATG, HMGs and infantry squads that are numerous at that time frame.
I do like IRHT on schwerer though, if not reworking IRHT at all. BGHQ promotes a lot of stationary gameplay by itself, pairing it with stukas means you have the perfect tool to deal with the same playstile you promote. A 250 on MechHQ will require serious volks nerfs and will make doctrinal Opel blitz useless, because a mobile reinforce platform for a cost effective troop as volks means steamrolling over allies and thast truly OP.