I agree, but the point I'm trying to make is that if the HoI4 Germany player is in a similar situation to the Germany of RL (i.e. tiny surface fleet, mainly land combat aircraft, little to no adequate landing craft) then it should have little to no chance of successfully landing in the UK. This isn't the same as saying 'Germany should never win' - in this instance it should only be able to perform Sealion if it has adequate naval bombers, a significant surface defence force and adequate landing craft (or be up against a stupid enough UK player that dedicates most of the Royal Navy in the Pacific/ Indian ocean, etc)
In the Manchester book it is evident that the ENTIRE British War Cabinet including Churchill EXPECTED a German invasion in the summer of 1940. Their hope was that Britain would fight in the streets to the last man and simply wear Germany down with a partisan war. Of course, that was never admitted at the time and never even mentioned in the Churchill autobiography of WW II.
They also expected in the Summer of 1941 that Russia would lose FAST. They were wrong on both cases.
Its also true, as mentioned above, that new sources of information appear every year and the later historians have more diaries and formerly secret documents published than the earlier historians.
Autobiographies, alone, are very unreliable since the authors will never mention anything negative about their own actions or views. Only biographies by professional historians and / or journalists with plenty of footnotes have any validity at all.
The way I see it is that the biggest danger to Great Britain is that their Parliament could have panicked, removed Churchill as Prime Minister and restored their previous pro-Nazi King to the Throne and then sought a tenable peace with Germany. The rapid capitulation of Belgium, France, Denmark and Norway are samples of that kind of outcome. Both Britain and the Soviet Union were in danger of panic, rout and capitulation. In Malaysia a superior British force routed to an inferior Japanese force and surrendered. In the Philippines a superior American force routed to an inferior Japanese force and holed up in a small area leading to their commanding general being ordered to desert his force and the rest of the force surrendering when they could really have defeated the inferior Japanese force.
HOI 4 should include the rout factor and the chance of panicky capitulations of all nations involved in that war.
For HOI 4 just the first 700 pages of the 1,000 of the last volume of the Manchester biography of Churchill are necessary to see many previously never revealed facts of that WW II era.
