i'm not sure. Exactly how many people have you run into from Sardinia? It doesn't come up very often.
My husband is born and raised in sicily, has green eyes. A lot of his family there is fair as well, light eyes, etc. Same with like you said...some northerners looking like they should come from the deep south.
My father is born in sicily too, and has light eyes, so do I.

I do agree with you though about calabrians, they are close to sicilians, mostly because they are geographically the closest to sicily. They're extremely similar.

With regard to people from Napoli, if they are speaking their dialect heavy, I can't understand a word of it.

Also between the mafia groups some people love to make it out like they're enemies or rivals for some reason. That's not the case at all.