But what would be OKW's tank option then? Okw has nothing serious to deal with allied medium armor by the time it arrives on the battlefield, except Puma. Nerfing it will create a gap that would be covered by what? I don't feel nerfing Puma is a good idea. If you think it's overperforming I would prefer to be removed and replaced with a PZIV J - except doctrinal (and very rare call-in) OKW has NO medium tank whatsoever.
Or you can nerf Puma's damage but you need then to increase its survivability somehow.
The Jagpanzer4 is a tank that exists. The JP4 does incredible work vs medium tanks and thanks to an abundance of munitions for shrecks and mines it is extremely difficult to properly flank.