Not read the thread but my belief is this.
Early in the war germany were dominant with weak tanks, but their airforce was the leader, and their dive bombers were very effective at removing obstacles to the ground forces.
Dive bombers were also proven effective against ships.
Subs were effective early war as well, they lacked in numbers tho.
The first question is could england have been invaded after the fall of france, in my opinion yes if the RAF was neutered. Some people claim it would be impossible because of the royal navy, but the royal navy in 1940 was not in a position to blockade the english channel, as an example when the dutch royal family was en route to england in a ship, it was all done hush hush, the navy were scared in the north sea of been sunk, not the actions of a dominant navy. A ship close by did in fact get sunk by some german subs. Also in 1940 anti sub tech was weak, so the germans e.g. could have made a path for the invasion force to cross with each side of the path flanked by subs waiting for approaching destroyers etc. and dive bombers as well on standby. Once on land beating a beaten down land army would have been easy.
With england taken out the picture suddenly things change a lot, all those large bombing campaigns against germany suddenly are not possible and is no staging area for a normandy landing.
So what about russia?
Russia initially faced almost the full brunt of germany as was minimal forces in the west in 1941 and they managed to hold on, when germany lost momentum late 1941, the luftwaffe was grounded, so lack of air support for the first time in ww2 showed that germans land forces suffered massively without air support, late 1941 they were also suffering from logistics issues, getting fuel etc. to the front line. If moscow was taken would russia have collapsed? I think that depends if stalin was captured. If russia did not collapse with fall of moscow then germany would need to conquer east russia, with their logistical problems that would have been a big ask.
With england taken out the picture, americans would definitely be supplying russia, and probably even more so than they were actually supplied as there would be no england to supply as well. Americans and any evacuated english forces would also possibly be landing in russia at some point as well to attack germany from the east. Bombing campaigns could be launched from russia as well, although I think stalin would only agree to it if russia on last legs.
As the war progressed germany fuel issues became more and more an issue which grounded planes and left tanks abandoned, in the actual war, in 1943 onwards a lot of german losses were due to having to abandon tanks and also lack of air support.
What if russia was not invaded? I think russia would have invaded germany, one of the reasons the invasion of england got cancelled was russia was building up forces on the front lines and the invasion of russia was to preempt that.
With all this in mind I think a considered win for germany would be this.
Invade england successfully. (england refused several peace offers so would never have agreed to peace)
Manage to take out moscow and kill or capture stalin.
Then at this point sue for peace with america and any remaining allies to end the war at that point. Leaving eastern russia sort of like southern france. Still partially independent.
