Nerf the crap out of panzerschreks at range? Requiring volks to close at least medium range to have a reliable shot at hitting something would reduce their threat to vehicles when massed.
Things like the USF AA Halftrack would have a chance to be able to maneuver.
That or replace with panzerfaust. Ideally a non-snaring panzerfaust that deals considerable damage, so as to sap munitions from the OKW player before schreks become available on something like Obers.
What are you doing with your USF AA halftrack? Those things are easy to manoeuvre and are deadly. Maybe you should try the AA halftrack from the OKW.... wait a few second before it sets up and Boom! already engine damaged and next shot... dead.
Already the Shrek almost always misses at full range.
And please stop with the shreks on Obers thing. It's boring. No one wants to use a four man team of expensive elite infantry where one of the men is firing a panzerschrek.