Discuss why a larger scope of activities of a physician partnership is likely to be associated with a more successful partnership?
I thought about your problem in terms of my experiences with these types of businesses as a practicing CPA. I can't think of any specific research that could be done to provide empirical data, if it is even available. Following are what I have observed.
Having a group of physicians sharing resources allows the business to expand vertically. They could, for example, have their own X-ray facility or their own lab which would preclude them having to send patients elsewhere for ancillary services. Having other services as part of their business would allow each of them to share in the revenues of that piece.
The solution discusses expansion in both the resources available and the perception by clients. Included is a discussion about how physicians share expenses in a partnership of dissimilar attributes.