If you get rid of shreks on volks the whole faction is gonna get fucked like ostheer is right now
They have T0 AT gun.
They would have fausts
They have mines
They have 2 tank destroyers non-doc (Panther, jagdpanzer)
They have a non-doc heavy
They have a doc heavy tank destroyer
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OKW had a ridiculous amount of AT potential, I fail to see how removing them from shreks would "fuck" them at all.
This pretty much gives OKW no Infantry hard AT, which is not an option, no other weapon in the game is locked behind vet.
Soviets don't have "Hard AT infantry". And a lot worse options than OKW in the destroyer department. And OKW have the cheapest, earliest, AT gun in the game.