Regarding Altobello; Even though he was Connie's GF, he could have been a Don in Sicily. He seemed to have long-time ties to the Sicily characters: Lucchesi and Mosca. He may have had family ties and business ties to Vito; maybe the cannoli business.
That's another plausible theory. More plausible that he was a Don of one of the other New York families (Barzini, Tattaglia, Stracci, Cuneo).
But he should have had more difficulty with speaking 'American'.
Maybe he was just an outsider like Sollozzo...
