Because Hitler was a dumbass who didn't understand strategy or tactics, and would always choose the wrong option when the stakes were highest, the Germans were probably inevitably intercoursed. Just before Kursk, Hitler pulled two divisions out of Op Zitadelle and put them into Italy. Brain dead. The Italian terrain was sufficient, and was some of the hardest fighting of the war. The USSR needed lend-lease and needed the second front, and demanded both from us, and got both.
It turned out to be a very good thing that the British talked us into doing North Africa first. Had that same force and commander invaded France D-Day could have turned out very different.
Indeed, Hitler was a dumbass who thought he was a military genius. It didn't help that he deeply distrusted the Prussian aristocracy that was the heart of the General Staff. He made so many idiotic decisions that shortened the war.
I read someplace that there was a secret debate in British intelligence whether they should try to assassinate Hitler should the opportunity present itself. The contra position was based on the fact that Hitler was making so many dumb decisions he was giving the Allies material assistance.