And much more expensive .
Get rid of the focus side ability on the Su-85, and decrease the cost to 310 mp and 100 fuel and things should be much better. There's no reason for it to cost more than a T-34/76 (its a turretless tank-destroyer, intended to be cheap, easy to produce after all).
Horrible idea, a good example is the jagdtiger costing more than a king in game when it wasnt the case. Or even panthers, which only costed 10% more to produce than a panzer in terms of price yet in game they are significantly more expensive.
Simply put this kind of logic can't just simply be put on one unit arbitrarily, but not others. The su85 performs well for its cost which is actually quite cheap. You all just feel underwhelmed because unlike the germans the soviets don't have some more expensive better tank to use. So they use the cheaper tanks. Its like transitioning from panzer 4s to panthers. But soviets stay on panzer4s.
Whats the key difference? Su85s are better vs armor than panzer4s, and still pose a threat to heavy vehicles. Considering 125 fuel what do you want?