They also spoke Hebrew, Greek, Turkish and Arabic. The linguistic differences between them and me didn't alter our belonging to the same people one iota.
If it did, then Siciliani, Calabresi, Pugliesi, Napoletani, Umbri, Toscani, Emilia-Romagna, Romagnoli, Veneti, Freudian, Lombardi, German speaking Altotesini and Piemontesi aren't Italians and the French in Corsica, Perpinyá and Hendaya aren't French and the Ticinesi and Genevois aren't Swiss.