I echo the idea that the only real way to get this resolved is for the three of you to talk - that is the only way that everybody will get the same story.
If she really wants a hierarchical set-up then she has the chance to voice that, and he has a chance to respond about what HE wants, and you can do the same. Then you can see whether there are areas of commonality there that you can explore, or if the gulf is too wide to cross.
My gut tells me that he will do all he could to stop this from happening, because I wonder whether what he is telling you is consistent with what he is telling her, and that needs to be resolved.
Please check out The Birdcage - an open, friendly Polyamory forum for all parts of New York State
"Listen, or your tongue will make you deaf." - Native American Proverb