Is she a dictator, or is she a natural leader? Perhaps she is horrible, or perhaps she is good at assessing the "job" to be done (e.g. the roles to be played) and assigning things to the various participants.
So the kids are tired of it - yet they keep coming over. So it can't be all that horrible maybe?
Why would you decide these kids can't come over? Because you are worried about their reaction and their own ability to say "no" to your daughter? But wouldn't they a) stay home and b) not invite her over there if she were such a raging empress of all she surveys?
I think it's great that there are several houses for a rotation of play - so much nicer than organized activities 24/7. And they have a group that continues to play together - so something is working.
It might not be your style of play, but unless she is totally cruel and belittling of others (vs. assertive and opinionated), I'm not sure why you need to intervene.
My son always had a group of kids like this - back and forth to various houses. The other kids were always coming in and saying that my son sent them for a) snacks b) supplies of some sort c) requests of my time. I got annoyed at first but then I realized the other kids were totally fine with this, my son was the natural leader, and no one was offended. When we were on the beach, he was the kid surrounded by other children from 4 years younger to 4 years older, working on elaborate sand castles with my son as the "director" of this cast. There were no insults, no one being called stupid, no one being criticized. In fact, they were praised for a "job well done." Later on, my son was the captain of the track teams and now is a project engineer at construction sites, using his Civil Engineering degree to manage various subcontractors who specialize in different tasks/roles. Looking back, I should have known this about him at age 6.
So, instead of taking away her leadership role, make sure she is motivating in her talk and not putting others down. If she is bossy yet kind, determined yet supportive of others' efforts, leave her be. If (and not until it happens!) she starts losing friends or they are crying or saying they want to go home, then you can address her style. But so far if there is no problem, and if she has a willing group of participants who come over easily and invite her to their house, leave them alone to manage it or work it out. For all you know, each girl is in charge at her own home and this is how they work it out!
I'd start making it a practice to stay out of their play other than safety issues or when there is severe conflict that requires your intervention.