You need to sort if evenly spilt the roles. You can’t have one Person US/RUS and another CHI/FRA.
UK will play a massive role in this game. It will have Africa and the med which I think will be a great battle, India, and Brittan which means the airwar for it along with D-Day sometime+plus the atlantic.
Been that it was in a pact with France and will have units there (BEF) they should be alligned.
Russia will be fun to play now. It will be hard to defend the whold front, but aircraft and where to put them will be important (scambling aginst SBR) and their might also be a tiny naval war for Archangel sea zone. And another fun thing for Russia will be defending aginst the orginal Russian attak. Been that China have a similar thing (land war) they should go togeter.
The leaves the US to go with the ANZACs, who where under use command, and battle together (coral sea).