There is something I dont get in the Castellano-murder. Gotti formed a group called the Fist. In that group were DeCicco and Gravano (maybe more, i dont know).
I'm reading Peter Maas's Underboss and Gravano told that Angie Ruggiero said to him: "Sammy you're very important to us, without you we cant do it!" (something like that). Sammy later tells that Gotti and Ruggiero were nothing without DeCicco and himself.

But, what doesn't make sense to me: Gravano was still a soldier a that time (according to gangstersinc.tripod.com, Toddo Aurello retired under Gotti's reign making Sammy the new Capo of his crew)...
So, why was a soldier like Sammy Gravano so important in the Castellano-hit?