I have Northern Italian friends who consider themselves very separate to the Southern Italians. The Lega Nord party was originally about Padania (Northern Italy) separatism.

Almost any group identified from the outside has internal divisions that they insist are incredibly important.

What did the Elves say? “To sheep other sheep no doubt appear different. Or to shepherds. But Mortals have not been our study.”

People can get really prickly about it, for example lumping all people south of the US border as "Hispanic" or calling everyone in the UK "English".