Or, would the Second World War have ended had the German nation actually attempted to invade Britain in September 1940?
My money's on 'Yes'.
Royal Navy, Fleet Air Arm, Bomber Command, Coastal Command, all thrown into the mix. And that's if they didn't make it to the shores. If they did make it, Then you would have the army too, and every civilian armed with a bread knife or better.
Speculations are cordially invited.