I agree that the media often refers to high level associates as "Capo's" and often anyone involved be it an associate or soldier is referred to as a "mob boss".
Also the highest ranking gangster in a region or town usually gets this. The two most prominent examples I can think of off the top of my head are Anthony Spilotro and Lenine Strollo, who were called the "boss" or even "godfather" of Las Vegas and Youngstown, respectively. They were both soldiers.
