Here's the deal, everyone is going to feel very different about "how" this works. My perspective is that it should be from a level playing field. Each side is taking a risk and must trust one another to work together. Private Practice doesn't work without full transparency and cooperation from everyone.
I have owned a private practice. When I moved to Australia, I still had every single clinician who started with me, stay. Why? Because we had built a partnership. Did I have more risk as an owner? Eh, maybe. However, that was my choice to make. I never laid that responsibility on to my contractors or administration team.
If everyone works hard and does their part, the business will be successful. Not one person needs to feel as though they have been taken advantage of. It just isn't necessary. I don't think more power needs to sit with any of the invested parties.