That's a 'what-if' scenario.
Instead of the Panther (Panzer III/IV development goes back to before the war), at the most basic they were probably better off with a medium tank that had the engine of the Sherman and had a lower cost, sloped superstructure that was only a few tons heavier than the Sherman.
Then their typical specifications of 5 man crew, 75 high velocity, 80+ rounds of ammunition, visibility, sloped frontal armor @ 80mm could be put into place.
That's what I think, anyway.
That would be the e-50, the best medium tank in ww2 never produced. Thanks to Hitler's irrationality he believed that warfare would be dedicated by larger and larger supertanks to the point of the p-1000 ratte. good thing he was wrong.