It was an important hit, so Dellacroce would have brought Gotti to meet with Carlo Gambino, meaning this is the guy I want in charge of the hit. Gambino didn't have to have a word, only a nod or a shake of his head.
Gotti could have met with Gambino and no words could be exchanged with Dellacroce doing all or most of the talking.

"I have this Nightmare. I'm on 5th avenue watching the St. Patrick's Day parade and I have a coronary and nine thousand cops march happily over my body." Chief Sidney Green