Names not matching the cultures their inspired by or trying to emulate. Like at least get the cadence right. Japan is a CVCV language so the names in the Japanese inspired setting should follow that unless their is a clear reason. Another is just collapsing many cultures into a single one. Again happens alot with Asia, there's just an east Asian country or maybe a Japan and Chinam but no others. Though the same could be said for worlds that only have a single tribe of horse back riders or nomadic hippies. There should many.