Cerone was never Giancana's underboss. Giancana didn't like or trust Cerone. Accardo did not have the power to exile Giancana. Giancana voluntarily went to Mexico and other places outside the U.S. and made a lot of money. It was time for him to go because of all the heat. Accardo had no power to murder Giancana. It was the other way around. Giancana was the Boss of the Taylor St. Crew which was the largest and dominant Crew in the Outfit. Accardo was connected to Elmwood Park and was a Top Level Advisor who was semi-retired. Ricca was the top Advisor and kept the peace. Accardo never ordered any murders without Giancana and Ricca's say.