The problem I see with OP Sea Lion is that the UK just isn’t anywhere near as big a threat as Russia is to Germany. Yes, the Germans can overcome the threat easily, but they still need a few turns to do so. Until then (and assuming you didn’t roll only 6’s when attacking the Brit fleet) you can pretty much ignore the UK until you can reduce the defending units of Moscow enough that Japan can take it before USSR can rebuild. (Yea, that means that Japan gets the money, but so what? Build only infnatry in Euro-Asia and Africa and wait until the Japs can take the US.)