I like all of those examples, but as an RPGer from the 70s I'm accustomed to a more benign interpretation of 'henchman'.
In a roleplaying game henchmen and hirelings are just npcs (non-player characters) who act as the main characters' gofers and, in the case of henchmen, occasional stand-ins. ("Henchman! Take care of my light work!")
Basically, to a guy like me, a henchman is just a guy who henches for you, and there's nothing wrong with that!