The sturmpio's long range firepower is pretty mediocre, even if they can survive at long range.
In addition, the Okw shouldn't really need sturm for anti-infantry duty by late game. The volks and ober practically fill the need for infantry combat. There's no reason to crowd the faction with sturm as well.
Giving the sturm to double equip schreck+sweeper would benefit the okw alot better significantly since mp44 volks is enough for most purposes.
The higher population on the storm also mean the okw struggle to effectively maintain minesweeper coverage.
Okw lineup is perfect for sturms to transition from an AI squad to support: at the start they are very high impact, as they begin to get outnumbered volks fill the ranks, as volks become less punchy obers come in.
Sturms used to pull double duty of both sweeper and shrek, which meant there was never NOT a reason to throw a shrek on them and thats bad design. By the time they are less effective fighting infantry they shouldnt perfectly amd thoughtlessly into a super support role. If you are worried about mines you can get a mine sweeper, but if you want AT there has to be some sort of drawback, reducing AI doesnt count if they are already combat ineffective when you need it.