I think if the doctors aren't in the same immediate practice, they are different opinions. I don't know a lot about it (just a patient!) but in my area, we have two main hospitals. The doctors have to affiliate with one or the other (or both) to be able to see patients and perform procedures at those hospitals. It really has very little to do with anything more than that, as far as I can tell. Just means that next time I break a hip, I might want to go to the other one so I get a different on-call surgeon, LOL, if I didn't like the one I just had, (Jury is still out on that, actually, but it makes a nice example ... and they never did tell my primary where I was.) My primary can see patients at either hospital. My OB could deliver babies at both, but had a preference about which one he'd rather deliver at. And so on.
Now, if the office is actually IN the hospital, then it's probably not at all like the situation I am describing and feel free to disregard everything I've just said.
It's just how I've observed doctors and hospitals seem to work in our area (except the ones hired directly by the hospital for ER stuff and so on).
((hugs)) still rooting for you!