I agree with BlueIguana on most of what he wrote.
Even the surface combat fleet was an economic raiding tool, rather than any assistance for Sea Lion.
Back in the 70’s the British war college or something like that wargamed it out. In the wargame, the Germans were able to make the landings, but the Royal Navy was able to eventually cut off the landings, which isolated the Germans, game over. I dont think you can say the attempt and landings were impossible.
Here are some if’s for a possible Sea Lion: If the Germans had captured the 340,000 Allied troops at Dunkirk, and the Luftwaffe had concentrated their air power only over the Channel and a little past the British beaches, knock out the radar antenna’s daily instead of going far interior, make the landings in July, there might have been a chance. My biggest problem at this point is supply…would the royal navy have broken into a heavily mined English Channel, and how long would that have taken? Would the Luftwaffe done a number on the Royal Navy?..their showing at Dunkirk was disapointing from that view and question. The lack of landing craft and the lack of appropriate kinds of aircraft(longer range FTR’s, and a very large number of Condor’s) make Sea Lion even ify’er.
From a AA standpoint I think a Sea Lion should be a possibility since you should not be saddled with the poor planning of Hitler, and then there is the ‘fun factor’ for the game itself.