I think this is a really common misconception that gets thrown around a lot. Bo will not be facing better competition in AA, the talent level at AAA is much better, and AAA also contains some of those "high-level" (i.e. top 100 prospects is what I assume you mean) arms who are more advanced. Those journeyman starters are much better than their counterparts in AA, because a lot of them actually have MLB experience. If Bo isn't ready for AAA then he shouldn't face the better competition as it could hurt his development, but the argument shouldn't be that he should stay down because he might bat against a couple more top prospect pitchers that aren't even as polished as the journeymen in AAA.