Also Nardi (that was an associate) and Danny Greene that tried to take the cleveland family.
I think it wasn't that dumb, they had a chance to win (especially with somebody like Licavoli as their main opponent).
About dumbest moves by the Mafia, I would quote Licavoli's actions again: if he really switched price tags on pants in shops and used stolen credit cards when he was boss already (or anyway, when he was already drowning in the money he made), even though he had no consequences from this, it still makes him look like a clown. Even Roy DeMeo or Sam DeStefano's motives can be explained at least with some psychological illness or whatever, but here with Licavoli I don't really get it....Unless the stories were just made up by somebody who wanted him to look funny.
