In my opinion what need the american mafia is that as used in the sicilian mafia every rats will be killed in a man ner or in another.
Leonardo Vitale aka the first mafia pentito was send to a mental asylum for 10 years once out was killed;lea garofano that testified against his husband was killed by him.
In american mafia Sammy "the king of rats" Gravano is still alive while in italy would be whacked after went out or first,vinny Palermo work in Texas and tony d'amico went back to NY but was only beaten.