Agree with you on some aspects... The movie is supposed to be based on SAC - not the iconic (possibly more than the manga) but Mamoru Oshii movies.
I’d expect Major to be closer to original manga/SAC characterization who is more light hearted and series is more adoptable - terrorism, immigration/refugee crisis,…

too short, way too scrawny... all in all, terrible casting. arnold from about 30 years ago would have been fine at this... even the casting the only japanese dude for aramaki don’t seem all that well fit.

the movie is to be based on SAC on the laughing man arc. if you watched the series in general, it not hard to conclude that most of japan is more likely slightly more diversified ethnically but more xenophobic due to the asian refugee issues, not full of non-asians...

I have multiple copies of the first (english, english v2, japanese) and the japanese vol of MMI, where is that note about western characters and society?