Hempy,
Can't disagree with your view, but a population of 170 million people over 5 to 7 time zones and some like the Ukrainians and the Baltic states very anti-Russia mass of a good few million. Remember Hitler did have some allies in Europe, not many I'll grant you.
Stalin also had his own eastern front to contend with and if he had come to an accord with the Japanese then maybe Stalin would also have had a war on two fronts. Germany did not have a land war in Europe on two fronts until 1943 with the invasion of Italy. He should have stayed out of North Africa but Mussolini needed the Afrika Korps to bail him out of trouble, same as in Greece.
If he'd stayed away from Africa and consolidated during 1942/3 he may have in my opinion with the Japanese on board, taken Russia. it would have taken time but it was doable.