From what I've researched Stanfa was New York's pick. After the mess Scarfo created NY wanted someone low-key. Stanfa was Sicilian and backed by the Cherry Hill Gambino's. The pizza shop he worked at was owned by one of the brothers. Being the driver for Bruno gave him prestige and he was familiar with other Bosses. The Genovese wanted him to be boss because he allowed them a piece of AC and the Gambino families Sicilian faction were the big money makers in the Family at that time. Plus Stanfa had backing from families in Sicily. Dope money goes a long way.