How about the Tank MG Gunner and tank support?

Maybe you can try to add some MG top of the T34/85 and Js-2 Tank? T34/85 add 7.62mm MG and Js2 and add 12.7mm MG. Also the ATgun can upgrade from 45mm AT to the 57mm AT or 76mm AT. The US army maybe you can add the m36b1 Tank destroyer for balance the US armor. the Britsh army maybe you can add the Black Prince Tank for replace the Churchill Tank
MK IV.

Nope, T-34s didn't use cupola MG(roof MG). About IS-2, we will see ;).

Black Prince is not going to be part of EF, as we have said before.