One player sat his two panther on my sides VP, so I set a SU-85 to push it back a bit. He didn't bother moving it, but after like 8 shots my SU barely got it to below half health, which I think is completely not ok. Those same panthers constantly kill like three models of vetted cons with their main cannon shots, panthers are in no way not any good at AI.
SU85 requires 6 shots to pen to kill a panther
SU85 has 220 penetration at far range
Chance to pen a 260 armor panther = 220/260*100 = 84%
I highly doubt you managed to miss or bounce 5 of your 8 shots, since the su85 is pretty accurate at long range, the odds are pretty low
And panthers dont constantly kill infantry, they are tank destroyers, not anti infantry tanks, and i cant remember the math exactly, but the chances of killing even 1 model are already really low.