They should of firstly in britain not been bombing cities because that didnt have the desired effect. They should of continued to pummel the RAF’s bases and planes. There is a lot of speculation that if they had done this the battle for the skies would have been won.
Then dont invade England just contain it.
Could have gotten around 100,000 british troops at dunkirk if they would have kept up the attack. Should have in hindsight.
No playing in the big sandbox. Those resources should have been used in the push into the USSR.
Attack headlong into the USSR . Forget pushing the northern front. Just contain it. Forget leningrad, just let it be. Focus on taking moscow first. The germans used 3 armies, a north, center, and south army when they invaded. Should of had one huge army to smash into moscow deploying holding units on your flanks of the center front. As soon as moscow was reached, attack south to get the oil fields. If moscow were taken i would argue that stalin would have sued for peace as he moved the capital forther east. Maybe Omsk. Anyway, stalin believed in world communism and if he were smashed he would think world communism would fail and that couldnt happen on his watch. He would of tried to stay alive and in charge farther east to further try to change the world with more time.