People have the accent of where they learned the language. If a guy learned English in the south, either by growing up there, or that was where he immigrated to from Italy, that's the accent he would have for life. We think of mob guys as having NY accents because nowadays most gangsters come from the northeastern US, but when there were families all over, I am sure there were different accents. Philadelphia and NY have very different accents, even though they are only 100 miles apart.