I think the only thing exempt from the rule could be China, who even pre-lore had it in mind there's no singular Chinese culture and there's multiple. Hence one of the old Beiyang flags that gave credit to the five most predominate cultures of China:

[img]https://upload.wikimedia.org/wikipedia/commons/thumb/4/46/Flag_of_the_Republic_of_China_1912-1928.svg/300px-Flag_of_the_Republic_of_China_1912-1928.svg.png[/img]

But even then, they still hate the piss out of Japan and the Japanese because of that Nanking an Unit 731.