Just putting this out there.... There are no bigs who will contribute 15/12 in their first year. Sorry!
And this is a good point. Olynyk could easily play 20 min in the nba, chuck up 5 more fg's (miss them) , still shoot at a high shooting fg percentage and score like 12-15 pts a game. But the problem he will face in a celtics uniform is, how much of a liability on the defensive end will he be to even get 5 min on the court. I have yet really seen in the past 3 or 4 years, Doc put a guy out on the court that is a liability on defense.
With Trey Burke, due to Rondo needing more down time or rest or 2nd unit has alot of problems getting set, will eventually get min to contribute for the team. He is also a capable defender.
For some reason i think Doc will really like Withey for his defensive capability, shot blocking skills, rebounding and ability to make the jump shot. Plus has very good bbiq.
The thing with Olynyk , though he may not be great defensively is, his team has only lost 2 games and i don't think he has got burnt by anyone he has been guarding yet. But i don't know, Doc is greedy for players that can play excellent 1 on 1 D plus team D, meaning weakside help, able to rotate on the pick and rolls well or ability to hedge etc. So would Olynyks exceptional offensive capabilities more than make up for his defensive shortcomings?