Hmmm, methinks that the only thing that could have rescued Germany from the coalition of enemies accumulated in 1941 would be a superweapon like The Bomb. The technological improvements of the mid and late war tanks were not quantum leaps. German production increases may look impressive measured against previous German achievements but are a bagatelle compared with Allied industrial performance.

Such increases that occurred were limited by Allied bombing from early 1943 and were partly negated by the need for ever more defences against bombing, dispersion of factories (which put even more pressure on German railways) and the loss of quality and efficiency in manufacture consequent on removing German workers to the army and replacing them with slaves.

Speer and Milch were able to squeeze more production out of the German war economy by the resort to wholesale barbarity but only within the constraints of raw material and energy availability, increasingly negated by Allied bombing. This wasn't much more than rearranging the deckchairs on the Titanic.