Keep in mind guys that the Gambino Family was divided into two factions at the time. And it seems like the two factions operated seperatly without the faction leaders interfering. Dellacroce had basically a free hand on running his faction. One example is when Dellacroce demoted Mike Caiazza, a captain in his faction, to the rank of a soldier without Castellano opposing. Gotti´s problem started with the death of Dellacroce. Up til then, Castellano could not demote Gotti because he belonged to Dellacroce´s faction. Normally, by LCN standards, a boss can make or break anybody within his Family. But this unusual set up between Castellano and Dellacroce, prevented Castellano to move on Gotti, at least while Dellacroce was still alive.