There are all different arrangements, Im sure. Murder Inc was made up of killers who were not official inducted members. They were hired or contracted to do hits. Even 'boss of bosses' Maranzano hired Irish killer "Mad Dog" Coll to kill Luciano. He arrived just a few minutes too late and Maranzano was killed before Coll arrived to kill Luciano or the entire course of mob history would have been totally different.

This particular case seems different. If Paul Cassano and Vincent Bruno were in fact members of the Lucchese Family at the time, then they shouldn't have been paid to take out Enzo Stagno, but simply ordered to do it. This was also pointed out by journalist Jerry Capeci when he was talking about the mythical $500,000 contract placed on Donnie Brasco's head. He said that if in fact there really was a contract and was carried out on Donnie Brasco, no Mafioso would be paid for doing it, that it would be done out of duty and honor. Hiring outside killers is different, but I'm talking about members here. According to the old rules and Mafia traditions, members aren't paid to kill, they're ordered to kill. In fact it's one of the agreements that they accept when they join, to kill on command. With outside killers, it's understandable that they would expect to be paid, because they never agreed to such arrangements and are not members.