At the blue white game (and despite really liking Waterman's game) I would comfortably take Bosko over both Waterman and Mag.
Bosko looked much more impressive offensively than Mag to me. In fact, in a vacuum, taking only the blue white scrimmage into consideration, Boskovic was one of the four most impressive players on the court out of the 16.
Totally agree with your sum of the parts comment, etc.