That was the most understandable explanation I've seen of how Chicago became part of the mafia and of Capone in particular

The one question I have is why was it that Capone was kept out so long for being Neapolitan ,i.e. non Sicilian, while guys like Genovese(Neapolitan) and Costello(Calabrese ) seemed to be already included with Masseria.?

Was it because Capone was in Chicago while Genovese,Costello and the others were local NY guys ?
And who was Torrio with -the Camorra or the Mafia before he went to Chicago?