Luciano agreed to the rule to appease the Sicilian hard liners. The wars probably would have continued if he hadn't. One of the reasons Bonanno tried to start on upheaval is because too many non Sicilian and Jews had equal or more clout than him. And, look how fast he was banished.

"...the successful annihilation of organized crime's subculture in America would rock the 'legitimate' world's foundation, which would ultimately force fundamental social changes and redistributions of wealth and power in this country. Meyer Lansky's dream was to bond the two worlds together so that one could not survive without the other." - Dan E. Moldea