US=Tau (Extreme emphasis on precision fires, mobility, and casualty avoidance, can honestly apply this to any sufficiently western military)
Europe=Deldar? (Extremely light these days, mostly high quality and mobility stuff, Sork marines have a larger arty pool than the entirety of France currently, etc)
Russia=Orks (Equal parts mentally retarded expendable infantry swarms and makeshift/looted/antique equipment)
China=Imperial Guard, desu (Heavily mechanized and land-based with mostly antique equipment with new stuff entering service, quality questionable but possibly okay)
India=uhhh Imperial Guard but with Severan Dominant flavoring, I guess? (Same as above, lots of antiques but without the new production)
Middle East=Chaos (Kinda fits, but could just as well be orks gameplay-wise, both are a mix of tard infantry and old armor with that 'herding retarded cats' mentality to actually do anything, only difference is that everyone in that region thinks they pull the strings)
Japan=Craftworlders (In their own little isolated bubble, high quality yet antique equipment, no numbers, no taste for conflict, have only deployed small highly-trained infantry groups in extreme situations so far)
Sorks= Iunno, Space Marines for lack of a better option I guess? (Westernized, has a lot of antique equipment, rolls way heavier than Japan for the most part, fully intends to fight an old-fashioned mechanized war)
Apply yourself, OP, you've mistaken meme political/cultural positions for playstyle. While that can inform you gotta do better.