Hm, I guess I understand what you are getting at, but you have to bear in mind: Whomever you invite into your life, will be part of the life of your other partner(s) as well. There has to be a certain amount of control a person should be allowed to have over its own life, don't you think? You have to compromise in this situation to some extend. It can't always go to your liking solely.
In my case, there is no hierarchy. Both are equal. Co-primary. But, there was the possiblity in the beginning of them saying: I don't want to live with the other. I would love to live with you but I don't want this person in my life because of you. That's totally valid. Especially if living together is possible in your case. We don't believe in veto, there is no control over another person. but everyone has the right to say "I won't be part of this."
When living together or just being partnered with another you find personal boundaries everywhere. I don't like how you but the plates on the table, why can't you look after your stuff, I don't want you to share personal stories including me with others and so on. And in regard to poly you will find boundaries when dealing with other persons in your life who have been brought there through your partner. Of course you will have a say about the way this is conducted.
Facts: 30, female, bi, v-type relationship with Sward (husband, straight, mono) and Lin (boyfriend, straight, mono), poly-fi and co-primary.