Indeed, I would say that in the mob, people who belong to the same generation of actors often become allies even across different families. And their most dangerous enemies are typically from the next generation within their own family. Castellano and Gigante were of the same generation, the status quo successors of Gambino and Genovese. Costello's closet ally was to be found not among the other members of the Luciano family (post-1945), but in the person of Albert Anastasia (Mangano family). Gotti was the upstart vis-a-vis Gigante much as Genovese was the upstart vis-a-vis Costello . . . . The real question is how did Gambino and the heirs of Genovese succeed in so thoroughly "legitimizing" their rule, such that Gotti's rub-out of Castellano appeared to be a heinous departure from the "rules"?