Those PG ratings are a fascinating indicator of how imprecise scouting is. Yes, one could question how accurate those scouts ratings were, but then a player's body and mental approach changes so much from high school through the first three years of college.
Did these kids work that much harder to become much better players than they were in HS? The stories of Adley's work ethic are well known. And of course their college teams, coaches, and competition have a lot to do with it. Still for kids not highly ranked by PG in HS, every year there is proof that your time in college baseball may change their prospects for MLB.