LaHair did nothing but hit for awhile in AAA too.
This isn't some new ad hoc rule I'm making up to be mean to Mervis. I've always been adamant that missing developing time for whatever reasons should count against a prospect, not for them.
Age is historically an extremely predictive variable for prospects. Prospects who are too old for their level should have their performance looked at with extreme skepticism no matter how good the very good reason is.
To make it pretty simple, start with the premise that most prospects fail. I need to see exceptionality in three areas to believe that a prospect is likely to be an exception to that rule: Scouting hype, age relative to league, and performance. Mervis has 1 of the 3, which makes him a prospect but no different from every other prospect. if he had zero he'd be organizational filler.
Someone like PCA, on the other hand, checks all three boxes.