Su85 is apparently useless along with the T34/76 and Katty since they are not worth it oddly. Also as I have heard from Gabba if a Soviet T4 Vehicle can arrive at the same time as an ostheer t3 unit then what is wrong?
Why you want su85 over bigger number of su76s?
Why you want t34/76 at all?
Kat is good, but, as i wrote it comes too late. 2 or even more minutes difference is significant and have very big effect in close game.
And the main question is why you want give ostheer free mid game without building quad? If they are not desperately bad you would be pushed from map with ht+grenblob and i wish you luck retaking your cutoff with t34/76 which would miss 9 of 10 shots.
Useless may be too big of a world but for me sov t4 overshadowed by t3.