My optimal G1 is as followed:
buy: 3 artillery + 6 infrantry and put it on Berlin.
Take south of france with 3 mechs and 1 tank(this gives the germans a foot in the meds). Put all units in range of Paris to attack Paris, backed by 2 tactical bombers. Take Finland. Take Bulgaria. Take Yugoslavia with all units in range of it.
Attack the british fleet at SZ100 with all aircrafts and battleship available and pray to god that UK scrambles so I can take out their airforce. (leave the rest unharmed with my airfoce, I can strike them next round again as I intend to keep all my planes on the western front).
destroy the DD and transport with subs in range of the coast of canada.
noncombat all units that didn’t move towards the Russian front.
All my purchases up to G3 are all infrantry and artillery and on G3 I’ll also purchase mechs, seeing how it goes on the eastern front. Russia is my main objective. I don’t use any planes on the eastern front except maybe for my 2 strategical bombers IF I have enough planes left on the western front the remaining rounds and if UK has something valuable to attack. If they manage to get too much vessels and my casualties would be disastrous, I’ll just let UK sit there and pull back with my planes to Russia. Allies can’t invade at least until US5 (and then my defence would still be way too strong in the West), so I can focus all on Russia.