Yeah, none or almost none. But still, there's rules for then because some people might be interested in this (there are, indeed, as de can read above). I have never been interested in then, but I have never been a player myself, only GM.
My own take? No rules apply. The rules as written don't make a lot of sense. It should be built on a case by case basis. Nothing prevents a 9th level wizard to hire more henchmen and officers as the player ser fit for his own purposes. There are clear rules for hirelings, it should be used here, as well.