I’ve seen the Germans take all 3 mainland French tt on turn one, however they failed to take out all of the royal navy, though in a risky gambit the German player did manage to sink the DD and get a hit on the AC off the coast of Gibtraltar. They killed off everything else except the BB abd DD in the english channel, which he paid for the next turn when this fleet sunk the German Cruiser and BB.
I think the best tactic for the Germans after the fall of France is to build 2 concentrations, one of fighters in France and one of Tanks in Poland/Rumania, and support these with Tac bombers
Sounds good, but don’t forget you also need ample cannonfodder (infantry).