Interesting that you bring this up as I just recently heard that pathologists are sometimes referred to as "the doctor's doctor."
Meaning, I think, that sometimes IM and surgeons in a hospial will consult with pathologists and ask them for help in indentifying the pathology of a disease; usually through biopsies or after a surgery to make sure they have clear or negative margins when resecting a cancerous tumor.
So, going along with the metaphor, even a parish of physicians needs a pastor to guide them.