@xlome_00 Sea Lion is one of those attacks where the threat is mightier than the execution. If you buy a carrier for the Baltic Fleet on G1, that’s a reasonable purchase anyway to protect your supply lines to Norway/Finland/Leningrad/Baltics. If you move the German Med transport to the central Med, it is protected by the Italian fleet and can reinforce Libya, which is a reasonable move anyway. If you then bring the Italian fleet to take Gibraltar and retake Morocco, that helps score your NOs, so that’s a normal attack. So all of these preparatory moves can be done with minimal cost to the standard Axis war effort.
But then the American bomber cannot sink the German transport without landing in either Egypt (where it will die on a G2 Egypt attack) or Caucasus (where it spoils the Russian NO.)
If they leave your Med transport alive, you move it to Western Med on G2 where Italian fleet protects it again, build a second transport in Baltic on G2 plus an extra plane, and now you are threatening UK with 3 inf, 3 tank, 1 CA, 4 ftr, 1 bmr on a hypothetical G3 sea lion.
UK can of course defend against this, but they will have to build a fat infantry stack in London instead of factories, ships, or air power. This could cost them the Atlantic fleet or at least force them to retreat it back to Canada; if they built a factory in Africa / India, they might lose it because they cannot afford to build units there on a critical turn. Meanwhile those infantry in London will just sit there inefficiently for several turns because there are not enough transports to ship them anywhere, and not enough warships to protect the Atlantic fleet in a forward position.
Your second Baltic transport is reasonably useful for shipping inf/art to Leningrad, and the extra fighter can of course be used for trading on the eastern front, defending France, etc. as usual.
So you never actually attack London in an AA50 game – you just quietly threaten to attack it, thereby forcing the Allies to waste much more money on defense than you spent on creating the threat.