This seems to me the most literal application of MoneyBall to faculty governance. Billy Beane had tons of potential as a baseball player but couldn't hit major league hitting. He was a "can't miss prospect". He had all of the tools. He missed. This experience stayed with him and when he became a general manager he determined not to trust his instincts but rather to look at demonstrated capacity to do the job.
In our field doing the job that means primarily teaching and scholarship. If someone has been a successful visiting assistant professor and has generated meaningful scholarship when given the opportunity, that seems to me the best reason to vote for them. The argument "but candidate X has never had the opportunity to write" or "she's so personable, I'm sure she'd be a good teacher" is compelling but only so far as it goes. When I vote against such a candidate I don't do so because I don't think that, given a chance, they could become a productive scholar or a talented teacher. I vote against such candidates because lots of great athletes can't hit a major league curveball.