Thanks Kyle. It's fun, but we are always in danger of heading into pure hypothesis, rather than building on what we know.
In the specific case of the potential invasion of Britain, we
know that Hitler was never really interested in invading the UK; that the German forces were ill-equipped to do so, and never in a position to undertake the kind of operation that would be required for a amphibious landing. (They never did a major one.) Operation Sealion was the real plan, but most attempts to 'run' it show it would have failed, and the later you get, the buildup on either side of the Channel would always leave the advantage with the defenders. The best chance they had was May-June 1940, and they took a break then. Sealion was famously 'postponed' later in 1940, never cancelled, but had the Germans redirected effort into amphibious landing equipment and not had a focus on Russia, even then the kind of drubbing the got in Crete would have been the result.
Europe may well have remained occupied, with Britain rumbling on the periphery, and maybe in five-years or a decade Hitler might've tried it, and there we are in pure guesswork.
As to Russia, I suggest an examination of the relocation of the Soviet industrial base. We've rightly noted America's achievement in wartime industrialisation; the Russian achievement, in relocating and gearing up their industry driven by Stalin's bloody approach was in any real measure a greater (and real) achievement. Much rubbish is talked by western nations about 'fighting to the last man' never surrendering etc, etc. I cannot see Stalin's Soviet Russia being defeated. I visited the mass graves in Leningrad (as it was, then) - it was a different level of war.
Anyway, interesting tabletop Generalling.
Regards,