Yes, this a big subject, perhaps a Medium article or two? I first heard about all this when researching my father's POW story in Stalag Luft III (the Great Escape prison camp). His diary (and others) quoted the German Luftwaffe as saying "You Americans are good guys, but you're fighting the wrong enemy" (the Soviets). Like you, I heard it from the movie "Patton", and many times from Eastern Europeans, plus learned of the efforts of Rommel, Hess, others to make a "deal". We were all trained to hate Hitler (for good reason) but realized later that Stalin was worse. Churchill/Roosevelt let Poland slip away at Yalta, but a larger "what if" would be "what if the Western Allies agreed to join the German Army & Luftwaffe to fight Soviets provided Hitler, SS, prison & death camps eliminated?" Soviets were fond of incessant bombing (like today) and were willing to sacrifice soldiers. They wouldn't have had air or sea supremacy, but had a good ground operation. I suppose many, many more Allied lives would have been lost, but we certainly had the tech advantage, and may have prevented the Korean War and elements of the Cold War (Soviets perhaps pushed back to Polish/Ukraine border). This might have had to have been initiated in 1944 to have been effective. Poland could have been freed without firing a shot (at Yalta). Controversy re: Japan is that Soviet entry in Aug. '45 helped convince Japan to surrender (but at the price of N. Korea, some coopting of China, Vietnam, etc). Bottom line, weakness of Germany late made Soviets look good (they were beatable), trading 1944 casualties like Battle of the Bulge for ones in Poland, Czech Repub, Koreas, Baltics then may have saved us a lot of trouble/casualties later.