Keep in mind too that The Gambino/Bruno relationship/alliance went back to the 1940s and likely earlier. When Bruno was boss, his Commission vote was often in absentia and by default went the same way as Carlo's family. And more specific to Scarfo-Leonetti/Gravano, those two families strengthened their bond not only with the rackets/construction in AC throughout the 70s-80s, but with some tit-for-tat murders as well. Gravano took out Johnny Keys Simone and Scarfo repaid the favor by taking out Frankie Stillitano for the Gambinos. Leonetti and Gravano seemed to get along well and did much AC-related biz together until everything fell apart later in the 1980s. And considering Stanfa's Italian ties to the Gambinos in Sicily and his "pass" from his Bruno murder involvement, the relationship continued into the 90s.