For a tank which is as expensive as an SU85, the Panzer 4 has been nerfed so heavily a few patches back that it is as ineffective against infantry as the panther.
From the perspective of the German player it makes no sense to go for a Pz 4 when you can call in a panther or StuG for far better AT and for anti infantry an ostwind is miles better.
The Panzer 4 feels like the abandoned child and the proof is in the meta game where I hardly see it built either when i play Germans or as Soviets.
Right now a Pz4 needs to get at least some of its anti inf accuracy for its main gun back. Its ridiculous to watch it fire 10 shots on a conscript squad and miss each one. Contrast this to the 85 fuel t34 which now is only slightly on par AT wise and can sometimes 1 shot an entire German squad.
No. You answered your own question.
If you want a hard counter to tanks you get a Stug and if you want hard infantry counter you get an Ostwind. Not sure what to make or need a bit of both? Then get a P4, but really going 1 of the other 2 is the more approriate hard counter for a situation. Having P4's to strong is a bad thing because it makes for boring playstyles because a player knows its safe to spam that one unit, as per previous patches.
The P4 and T34 situation is balanced now. T34 does not counter a P4 in a 1v1 engagement.