Of course this is true.
Without M36 USF could only fight mediums at best, because Stuarts and the US Pak do not have the pen to deal with anything heavier than a Stug. So the M36 needs the pen to damage a Panther and even heavier. It's not well designed, but that's what we got.
Yes the M36 should be able to fight the Panther and heavier.
On the other hand it should not be able to Penetrate the Panther with 100% chance to hit and penetrate at range 60 nor it should be able to completely shut down the PzIV.
Superior allied infatry and TDs that can penetrate axis armor from range 60 is bad designed that reduce the diversity of built orders.