I would say that many groups whose monikers are taken from the names of one or two members of them work within the idiom of jazz. A good example of that is Count Bassie, whose eponymous orchestra accompanied him in his musical journeys. Then again, he established the band and one of the rules of the scene claimed the handle of the collective should honour the founder. True, I might have overstated the reason, though we must admit there might be a grain of truth in that, since jazz continues to be a genre, where an association follows the leader. He sets the parameters and the others find their way within them. Sure, things are changing, but you can still notice, when you check your listing for jazz concerts, they mostly advertise the latter with the cognomen of the soloist.