I agree with everything JC posted. The blue collar wing of the Gambino family (and other families' traditional rackets) were sitting-duck targets for law enforcement, and would have tripped up Dellacroce sooner rather than later--just look at how much trouble Quack-Quack's drug dealing caused. Big Paul may have lacked Dellacroce's personal force and earned loyalty, but he was a smart businessman and had plenty of "legitimate" and semi-legit interests to keep the family going.