Yea, Mushmouth and the others are mentioned in the Organized Crime In Chicago: Beyond The Mafia book I mentioned earlier. The Italians had been trying to take over the black numbers racket since the Capone days. Some others simply worked with them instead of outright trying to take over. It mentions Giancana actually sought permission to perform an outright takeover and Accardo granted his request, but Roe proved to be a tough challenge.