Yep, the later tanks took the "blitz" outta blitzkreig.
As to your last point, you have some case for an arguement there, but still they could not be produced fast enough. That really is what it boils down to. 1400 Tigers vs 50,000 Shermans made and not even counting the T-34s yet alone other makes.
"Do not forget your dogs of war, your big guns, which are the most-to-be respected arguments of the rights of kings."
- Frederick the Great, King of Prussia