*funny babbling here*
You are forgetting the SU-85's main weaknesses:
1. Turretless, therefore very flank-able and extremely vulnerable from behind.
2. It is a glass cannon, +0 HP at Vet 2 is warranted as it takes skill to use it properly in it's only role which is a TANK DESTROYER.
3. If axis mediums are trying to go "toe to toe" frontally against SU-85 and get beaten off, this is normal.
4. Extremely vulnerable to AT infantry.
If I was Werhmacht playing against you, I would use a PAK-40 AT Gun supported by a panther in blitzkrieg mode and your SU-85 is toast. If I was Oberkommando I would use ATG with a JP4.
Just because you are using one unit particularly well, doesn't mean it is OP. Some players are braindead and don't know the counters.