All I’ve got so far is a few basic opening notes:
I’ll need to playtest my ideas about a mechanized Russia, but obviously Russia moves 6 inf back to Moscow from the Pacific side. I usually retreat the 12 and then on R2 move them back to threaten the Japanese to try and freeze Japanese troops from being able to head south to attack China/UKPac. On German side… not much you can do if Italy is successfully can opening for Germany. If not, you just try to group you inf together and look for a counter attack opening that will delay the German advance an extra turn. If Germany is doing Sea Lion, Russia should try to hit southern Europe. Its much harder for Germany to get rid of them there compared to using their transports to hit you on the coast of the Baltic.
UK needs to assume Sea Lion. Their margin for being able to stop Germany is pathetically small if Germany can bring 10 transports and its air force to London (to stop that requires having 17+ hit soakers and 5 fighters) This means a UK1 activate Ireland using your mech (its a landing spot for U.S. bombers if London falls) and buy of 6inf and 1 fighter (and if Germany looks Sea Lion, UK2 buy of more inf and any U.S. forces you can bring). If no J1, you can NOT spare a fighter from London for Taranto. No scrambles on G1 unless your fighter can/will kill 2 or more German air but killing the German battleship might be worth the fighter in Scotland. UK also ignores Italy in Ethiopia other than walking 1inf/1art to Anglo-Egypt Sudan. It’ll cost you nothing right now. UK cares more about sinking Italian transports and getting Persia. If no J1, I also take Sumatra. Taranto raid and kill Italy’s Malta ships. UK’s goal is to 1) keep London, 2) keep Italy from getting N.O.s, and to build a factory in Persia on UK2 if no Sea Lion, and send 3 fighters to Moscow every turn you can (UK3-5)
US… if a J1 you need to send a bomber and fighter to London. If transport at Canada sank G1, they’ll need 2-4 more bombers purchased US1. If Japan never attacks US and Germany gets London, your 5 bombers can sink the German fleet and land in Ireland (hopefully) on US3 as consolation. I prefer to build for the Pacific theater after that, and leave Germany for Russia/UK (mostly… other than help from the 3-5 U.S. bombers that join in). The goal against Japan is to get enough U.S. ships/planes to threaten and take sz6 if Japan commits to hitting India. Iwo Jima is nice to have, too, to stage bombers from. Caroline Islands are great, but in range of a LOT of Japanese planes, so can be dicey, so be careful. I prefer a couple of US carriers and a few subs, but mostly destroyers to soak hits from Japanese planes. The goal is to either freeze the Japanese advance or occupy sz 6 around US 5/6 and start convoying and bombing.
UKPac, China, ANZAC’s job is to cost Japan planes whenever possible. Slow them down and cost them money if possible. This means sinking transports. Grinding away any Japanese troops being used to take islands. Retaking money Islands if you can keep it for 1 Japanese turn and leave 2 inf there to defend and hopefully cost Japan troops.