Strictly speaking in the context of a consensual BDSM and my own personal preference view of such relationship...
Are there any hierarchies in play? Its a bit of a moot point. Yes, I submit, I respond to his dominant chemistry and behavior, I obey and do things I find difficult and wouldn't do otherwise, things where he pushes me out of my comfort zone. But make no mistake if he did something to cross an absolutely untouchable limit (for myself) I would have no problem taking control and top/ over domme him. Its not that I cant dominate or take control, I can and can do it well, but I am not dominant, it does nothing for me. I get no satisfaction from it. Our dichotomy seems to be, you see it as a vertical, while to me D/s is a horizontal power exchange.
He says it better: