Winter war would be quite bad idea tbh.
First there comes possibly arty and\or air strikes. Then you can see from the distance the human wave of soviet soldiers and tanks combined. And when they get in range you just keep firing those poor bastards 'til they retreat or get too close. And only AT weapons would be pile of wood you use to immobilize the tank and then throw molotov in.
(bit overgeneralized, but it is pretty much true if we speak by the sake of realism - which 3\4 of you people always want)
Continunation war would play much more beter.
Therefore it would need a couple of maps from Continuation war (such as Mannikkala) which would have Finnish StuGs and maybe captured T-34 and KV-1 also.
StuG would be the best choice for sake of realism. Sure they did have captured tanks, but which you would use more - captured tanks which have been hard to acquire and might have bad overall quality (considering the tank might have been KOd first, then repaired again) or fresh and new supplied tanks?
Captured tanks really would not hurt at all, but generally most of the people already keep complaining about the current Mannikkalla that finns having german weaponry - even though it is historically correct in it's own ways. But "for the sake of realism" they want the soviet weaponry back. That is also historically correct.
So we are dealing with two sides: the other one who gives nice ideas and approves them because they had something like that, while the other part disagrees and causes huge riot by the fact that "zomg historical accuracy is ruinzored!"
Good example would be those ideas about having 'realistic' stamina system. You can't implement one without taking too much crap into account