"To try and answer your question, “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.?”
I think the best answer to your question is to say that Capone was originally mob-connected by his affiliation with La Camorra. It was his South Brooklyn Camorra superiors who first backed him, and later sent him out to Chicago. So he was always under that “umbrella” so to speak, as opposed to being “with” the Mafia, per se.
So Capone owed his fealty — and he basically always operated — within the realm of the Napolitani/Calabrese underworld.
Whereas Genovese, Costello and some other non-Sicilians remained in New York and became very early affiliates of the Sicilians, such as Salvatore Luciano and others."
That answer makes perfect sense of what could have been seen as an inconsistancy. So I would guess that Torrio would have had same type but earlier Camorra based transfer to Chicago as Capone?
Did Torrio ever become a member of Cosa Nostra ? Did he continue on as Camorra ? Was he ever offered a Cosa Nostra membership? Would he even have accepted a vMafia membership ?