I'm obviously a little prejudiced here, but, a thought or two...
I've been precepting for second year PA students for thirty odd years, and my impression is that the specifics of license and title are less important than intelligence and experience. The ability to think logically and manage differential diagnosis can be taught, to a certain degree, but, does require a certain native ability. Our office has hosted several NP students as well as a few 4th year medical students. Although we do preselect our students, requiring from their schools that they be in the top quartile, the same needs for success apply across the board.
If there were a good way to test for critical thinking, as well as interpersonal skills you would have an easier task.
Good luck!
