But I do not see why you can't understand my arguments...
1. The Me262 should have been pushed into production a lot sooner, so by 1940 you have like... 500 of them flying over the channel.
2. The Germans speed up the Elektro-Boats construction, they go into Scapa Flow and sink all the British ships. The channel is mined. The Italian Fleet makes an appearance outside Gibraltar, engages the Brits, crosses the straits and moves towards Great Britain. At the same time, Franco gives in and lets the Germans take Gibraltar.
3. The German Army engineers build pontoon bridges over the Channel, so that the Panzers don't need to use the barges but simply roll over the channel. They assured Hitler anyway, that the Channel crossing would not be more difficult than a river crossing.
4. German flying saucers fly over from the Antarctis and zap Churchill.
So? I find it highly plausible that this could work!