I think they do way too much dmg against weapon crews.
I had about 3 MGs, didn't look after them for about 10 sec and suddenly all of them (+ one unvetted volxsquad covering them) were lost to a single partisans squad.
300MP? Seriously, they do better against crews than commandos.
Also, I really don't like those "they suck vs MP44" or I remember a DEV comment on IS2: "WH Marder will easily kill them".
The problem here is, that maybe there's a very effective counter for all USSR-stuff, however, it's unlikely to have them all in one single match. The soviets should be nerfed a bit, so also other units will have a change against them, in contrary, the axis shouldn't have a super-counter like said MP44s or Marder (not everybody has damned TOV!).