Part 1: WHAT GERMANY DOES.
The most important thing that Germany must do, is build several transports on G1, and put them in position for sea-lion. So, effectively, you could invade England with 8 ground units, and up to 8 planes. That usually wins no matter who your facing. So on G2 you could likely take England AND invade Russia from the west, using your massive G2 money for Russia.
But let’s assume low luck…you lose two fighters and a tactical bomber in your Atlantic battle, and all your subs. England still has nothing to protect his coast. You will still be able to invade with 8 ground units, 2 fighters, 2 tac bombers, and a bomber.
Part 2: WHAT ENGLAND DOES
No matter what the outcome of the first turn was, England MUST prepare for sea-lion. That means buying no less than 9 infantry to place in London. Depending on how well you did in the North Atlantic, the English player will most likely have to abandon a Taranto raid in order to protect is coast. If there are no ships in the English Channel, than Germany can just continue to land soldier in England at will.
PART 3: THE BENEFITS
Germany can control what England does in the first turn, and if the English player does not do the above moves, then London will fall. But let’s say that the English player does do well to protect himself, and defends London properly. This is just a greater benefit for Germany.
- If London is not defended
-Sea-lion can take effect
-You will receive 30 IPCs from London, and another 8 per turn from the territory
-You eliminate an English player
-You free up Italy in Africa and the Med
-You force America to attack England instead of mainland Europe later on
-Your navy is free to act where it wants to***
-Barbarossa will come much quicker.
-You have that same attacking force to invade Leningrad***
-You free up Italy in Africa and the Med.
-You can mobilize more units along the Baltic sea.***
***All with the same 4 transports
Without a doubt, a planned sea-lion is the most effective move the Germans can make. Executing Sea-lion in G3 may become risky however, to to the fact that it will take longer to invade Russia. If your invasion into England does not seem like it will work, invade Leningrad, it will be nowhere near as well defended as England.