It seems like pedigree is a big deal to their scouting department. They are willing to draft a 5 star high school guy even if he struggled in his time out of school. Smart, Langford, and Brown are examples of this. Tatum too to a certain extent.
Based on that, I could see them taking a swing at RJ Hampton if his workouts were good. I think the willingness that he displayed this last year to fit into a scheme with veteran players without having the ball and while working on his defense will be appealing to CBS and Ainge.
I like Bey alot too as a guy similar to Grant Williams who is a really hard worker and smart basketball player.
Ramsey, Stanley, and Lewis also seem like the Rozier-Edwards type of picks that Ainge loves to make.
Riler, to me, looks like he has the potential to be a versatile on and off ball playmaker ala Brad Wanamaker.
My best guess would be Hampton, Bey, Ramsey, Stanley, Lewis, and/or Riler will be Celtics come draft day.