Sherman 76mm is not balanced against T-34/85 because it not fighting T-34/85 it is fighting PzIV and it replacing T-34/76.
Even if it balanced against T-34/85 it would mean that T-34/85 needs slight nerf because it one of the most cost efficient main battle tanks.
It needs to be balanced within the soviet roster to be picked over other soviet units. Assuming that core unit is balanced already against its opposition through other mechanics.
If okw and Ostheer both had a doctrinal Panther with 4 levels of vet you can't cost them the same because "they don't fight panthers" as the factions are designed with a certain cost effeciency in mind and the doctrinal unit has to match up with the factions established cost effeciency.
A 4 vet Panther would need to be cheaper for OKW and more expensive for Ostheer despite being the exact same unit-the only difference being the established expectations in the faction.
Such is also so for soviet doctrinal tanks.
The t34 is cost effective, but this is offset elsewhere in the factional design.
The 85 is a great tank, especially compared to the 76mm t34 BUT compared to the stock t34 you sre paying nearly 50% more and THAT is reflected in its performance. Otherwise the Ostheer /okw overlap units would HAVE to be cheaper than the OKW ones due to the lesser scaling if we don't take the surrounding faction into account.
The context of the faction and the establishmented balance therein matters.
Compared to the unit its expected to replace in the soviet faction I'm not certain the new Sherman will be worth its price point with nerfed vet.