I wouldn't have an issue with IS if they didn't drop their weapons at vet3. What I do have an issue with is the UC, AEC & mortar pit.
That would already go a long, loooong way. 1 guy wrote before, just pick them back up... But most scenarios that either costs you quite some micro that you loose somewhere else, dps as your squad moves, or worst of all, just not possible, 5 IS members stand arround, a mortar shell hits them whilst they are in a fire fight, 3 men die, bren drops, what do you do? Wait under fire to pick the weapon up? No, you just retreat most of the time. But thats with all weapons and its ok, just the scoped einfields make this happen too often.
I still think though they dont stand up to their price even then, compare them with vet 3 double 1919 rifles, who again, have a snare and better vet and require no tech for 5 men. Yeah I know it's doctrinal but still, also works with bars.
Especialy the lack of snare is crucial to me, they just need more firepower to make up for it. As OKW you have shrecks, you dont even need a snare (falls and pfüssiliers have it anyways) but as brits with piats you simply need to excel in AI to make up your lack of AT as a faction because you will need to invest more MP into AT leaving less for AI.
A firefly even looses to a p4 if they have a straight out gunfight both needing 4 shots to kill one another with the 10s reload vs 6.4 or smth like that. Without a snare the only way to keep that p4 from rushing in is to have enough AT to simply outmuscle him.
This NEEDS to be represented in better AI power. My 2 cents.