Well, if we want to explore the industry theme the real decider was that German industry (just like the British) was based on hand-assembly by skilled craftsmen, while the US had already adopted Henry Ford's idea of assembly lines and streamlined production that allowed huge numbers of items to be turned out each shift. It was only a matter of time before the smaller German economy was out-paced by the larger and more efficient US manufacturing base. And the Soviets were soon on a par with the US - the T34 was turned out in numbers similar to the Sherman.
I think it was Admiral Yamamoto in Japan who predicted that if the war in the Pacific wasn't won within months of Pearl Harbour then the US would inevitably crush Japan just by sheer economic resources...
But going back to the original subject I'd say it was the unbelievably reliable and abundant US M3/M4 series of tanks and their Soviet counterparts on the T-34 hull that did the lion's share of winning the war, despite their many weaknesses.
Excellent post Sir!
The Russians built about 55,000 T34 tanks, and the USA built about 50,000 Shermans. But the T34 was a much better tank when put in capable hands. Neither were a good match for a Panther or a Tiger, but there were so many of them that the Germans had trouble resupplying ammo and gas to their armored groups.
I'm certain that a newspaper photograph of an assembly area building B24's by the gross must have been a scarey thought to both sides of the Axis powers. They were building Shermans so fast that they actually had to slow their assembly lines down! The samething for B17's and B24's
Back to the PTO a bit. Shortly after the battle of Midway the Japanese Naval Staff was known to say that the war was lost!