Right castellano wasn't a gangster and he didn't earn his stripes, so a lot of the street guys resented him for it. in New York where there are five families that operate right on top of each other the bosses maintain order and good relations and like you said they can make a lot more money being partners than competing with each other. yes the geneveses were definatly a force when frank Costello was the boss it was said that no1 could become a judge in the city without his approval. but then Costello started to distance himself from the street, started surrounding himself with high class people, saw a psychiatrist etc, then it was gignate that pulled the trigger on him so a more street guy like genevese could take over, I think were starting to see a patern .