From a pure baseball perspective - being on an MLB coaching staff shows his baseball acumen is plenty to be a collegiate HC
Recruiting and managing the pitching staff are the difference. Also just the overall calendar and adjustment to college vs the pros. Drastically different. Hiring a legitimate pitching coach could bridge that gap.
I would rather have a proven collegiate HC like McDonnell but Jon Jay or someone like Tulo or Matt Holliday would certainly check a lot of boxes and move the needle. They also know what recruiting and the overall collegiate calendar looks like.