My first thought is that DAnny, this week, once again stated his belief that this draft was not as good as people are making it out to be. I believe he is correct in the sense that not all those projected to be in the draft will come out AND that there does not seem to be a truly great player in the draft - I think there are perhaps 5 that could ascend to that status with continued development.
Working on that premise, I am not sure DAnny is interested in accumulating more 1st round picks for this draft although your scenario has them getting top 3 picks. I think Boston would need to exchange their current 1st rounders with Orlando and Utah in addition to the players before either team would consider giving up a top 3 pick.
You always want to win the trade. In this case the C's are trading away 3 of their best veteran players, including their only all-star, in exchange for a couple of expiring contracts and a couple of 1st round picks albeit top 3 picks. That's a clear indication you intend a long-term rebuild. Rookies are not going to turn things around in short order unless their is a sound veteran presence already present. What you suggest leaves Wallace, maybe Bradley if he is resigned and ... Sully as the veteran presence on the C's? To me that says it will be at least 2016-17 before this team is ready to compete for another banner. It can get done a bit quicker than that, imo.
Rajon Rondo, Phil Pressey
Jerryd Bayless, Chris Babb
Jeff Green, Chris Johnson
Brandon Bass, Jared Sullinger
Kris Humphries, Kelly Olynyk, Joel Anthony
Colton Iverson (stashed overseas)