[Suhiir]

Tank (and aircraft) production is never as easy as it seems on paper.

Sure you can whip up a set of blueprints in a few days/weeks and a prototype in a few months. But then the fun begins. Manufacture. It takes time to build a factory, and will the output from that factory be sufficient, do you have access to the material and manpower needed. Post war development runs into the problem of can you get the money.

The WW II Panther was a great tank on the battlefield but suffered from severe mechanical problems due to design flaws. Read up on the road march to Kursk, three of them self destructed due to internal fires and nearly half broke down. The Sherman was mechanically very reliable and easily a match for the Pz III and IV that make up the vast majority of the German forces. A typical case of is it better to have one great tank or ten mediocre ones.

As to a link between the Panther and the post war Leopard ... everyone learned from the design of the T-34, which the Panther was based on, so indirectly the Leopard was a direct result of the Panther, but not in the way most people would think. Tank (and aircraft) design, like any other sort, learns and benefits from whats been done previously.