My proposal is to hit 2 birds with one stone.
Move Panzerschrecks to Sturmpioneers as they originally were. But also let the starting Sturm squad begin with a free Panzerschreck in hand. Not only does this reduce Anti-Infantry firepower on the starting unit, but it gives OKW an early counter to the fast M3 / WC.
and how are the volks going to scale then? without shreks they lose all purpose