They say John Torrio was the arbiter between Costello and Genovese. Torrio dies in April 1957 and not long after that Vito Genovese sends the Chin to pull the trigger. There was a little over two weeks between Torrio dying and the attempt on Frank Costello. If the story is true that Johnny Torrio was the arbiter, then it would make sense for Vito Genovese to wait, and only chip away small parts of Costello's powerbase. Torrio was both respected and feared, he was having problems with the Profaci family, mainly Frank Profaci for an unknown reason. Torrio was living in Brooklyn after he left Chicago. He could have joined either the Gambino or Genovese crime families but the logical and smart move would have been to join the Genovese crime family.