The thing about Dieng is that he is not great at anything. Yet he is good at alot of things. See his stats after a game and nothing stands out, until you turn your head and realize he just finished with 9 pts, 8 rebounds, 3 blocks, 4 assist, 2 steals. In addition he is very versatile and able to guard four positions (C,PF) and (sf, guard - temporarily, PNR).
Based on this fact alone he should be a 1st round pick but maybe from 20-30 range.
There is excitement and potential, if he can add on 20 more pounds, what else more he could do on the court. He has very good bbiq, not turnover prone and a winner. But natural basketball skills are not there. You need a point right now, he is not the man who will help you get that. Rebounding could also be better
The celtics especially with KG and PP leaving, need to hit a home run as soon as the 2013 pick. Guys like Giannis, Saric fit the bill bc of their leadership qualities and "i can carry you on my back" capabilities. You also have guys like Kentavious Caldwell Pope that can score in so many different ways, and consistently be a 20 point guy (and we are hurting for scoring). They might be better options for the celts.
Dieng on the other hand would be a better pick for a team like SA , who have already are strong in almost all areas , except needing a guy to step in when Duncan needs to rest