No it's not because I'm setting a boundary that no European country is that dissimilar to another one.
I mean as Mexico isn't considered NA, there are no actual countries in Europe of which the cultural differences are that high.
And also Europe is a bunch of countries, perhaps Portugal doesn't have the most in common with idk Poland, but you can def trace a line
Portugal->Spain,->France,->switzerland->Germany->austria->Poland or something, you can't do that from NA to Mexico and that's why IMO Europe+cis is considerable as a region