I'm not talking about a Thug. A "Gangster" who is a Made-Man is choosen from his background on his behaviour, his quietness of business and what he does for a living. Drug Dealers in La Cosa Nostra later get found out by senior members and are forced to retire or get killed which Castellano did to people who did do that sort of stuff. A Made-man is usually someone who has a nice car, suit and good personality.