In Murder Machine it states that Roy grew up on Ave P across the street from Joe Profaci's house and became close to Profaci and his family and spent time inside the Profaci home. Profaci hated the Galllo's and ordered Joe Gioelli murdered and had Carmine Persico attempt a garrotting on Larry Gallo in 1962. After Profaci died in 1962 his underboss Magliocco took over until The Commission demoted him and appointed Joe Colombo as boss at which point it became the Colombo family. Maybe Roy hooked up with Gallos after Profaci died and got scared after they had Colombo whacked in Columbus Circle.