We went over this is the last thread. There's a mix in all of them.
FN has bits of Jap and SEA cultures, plus Meso American natives
WT is obviously Eskimo-Aleut, but the north has a weird Venice-like city
EK has a ton of stuff. China for sure, but sand benders are arab/Berber influenced, Foggy Swam folk are American South, Kyoshi warriors are very japanese,
AN have obvious tibetan routes but there was that one indian guy and buddism stretches all over asia.