There were 3 things the Germans needed to have done to probably win against Russia-
1. Increase Luftwaffe Strength, In 1939 and 1940, German Tank and Plane production was far too less, Increase in Luftwaffe Strength and possibly Tank strength was the key (how to get steel? Scrap all Surface Fleet construction).
2. Force the Allies to contribute more manpower and strength in the initial assault itself (Romania, Hungary, Slovakia, Croatia, Italy and also Spain, Occupied France and rest of Occupied Europe needs to be used to attack), with 3 vast armies (manned by these allies) operating behind the main army groups doing 3 things- Railway construction, road maintenance and anti-partisan duties and finally mopping up the survivors. Instead of the "unmentionable/useless things done". Also force the Finns with bribes etc to attack Leningrad in the fall of 1941, send the entire Finnish army from North and with conjunction with AGN, Leningrad may have fallen in 1941. Increases logistics supply and reduced partisans and bottlenecks.
3. Go all out for Moscow in late August itself instead of the Kiev Battles using the 2nd, 3rd and 4th Panzergroupes with the 2nd, 4th and 9th infantry armies doing the "Flank protection" and mopping up. If Moscow falls it is "Game over" or at-least a good chance of "some bitter peace" type event.
For all this to happen, a version of the Count Schulenberg plan - basically liberation of Baltics, Byelorussia and Ukraine and Caucasus states should be the basic plan of attack (wishful thinking considering the murderous psychopaths like Hitler, Himmler and Heydrich will never support it).