Damien should go if he gets a credible 2nd round projection. Why risk injury?
Bo should stay.
Saban usually recommends his players stay unless they are first rounders.
RBs might be different because of their limited shelf life/injury risk. The problem with Harris coming out early is that there would be several RBs ahead of him, whereas if he waited until next year he could be one of the top RB prospects in the class.
This year's draft class could include Saquon Barkley, Bryce Love, Nick Chubb, Kerryon Johnson, Derrius Guice, and Sony Michel. I'm afraid Harris might get lost in that mix.