The Russians had heavy tanks too. The Joseph Stalin series of tanks 1,2,3. These where the Russianicon answer to the Panther and Tiger. The M4 was obsolete before it left the factory that's a fact, we had no real answer except to up gun and stack sandbags, numerical superiority didn't hurt either. Even more reason to admire the crews who knew they out gunned and out Armored by just about every Germanicon AT weapon and of course tank on the field.