So lets say that Stalin and Hitler both act significantly smarter than in OTL. Hitler does not do the Holocaust until after WWII is over, keeping the Jews in the ghettos, and lets the Wehrmacht have control over the war in full. He also acts more decisively at Dunkirk and won the Battle of Britain, forcing a UK surrender. Stalin has been less intense with the purges, notably sparing Tukhachevsky. He has also let the Red Army have control over the war. So in this scenario, how does Barbarossa go? Who wins?