If anything, I think this points out relying on any ONE method to build a team will get you nowhere. In order to build a contender, a GM needs to be able to acquire talent from all 3 methods: Drafting, Trading and Free Agency.
based on track record, I believe this to be Danny's approach. for all those bemoaning Philly's approach as the only viable one, they're missing the boat since Philly has neither the assets to make trades (unless they're giving up their high picks or players taken as high picks and hence would have no players from the draft) nor are they likely to be a FA destination until they become a contender (or at least a playoff team) which is several years away.
Philly has better trade assets than we do. They have more cap space than we do. We may be a better FA destination than Philly but not by much. I agree with Philly's approach not to let average players, specifically average vets, get you meaningless wins when you are rebuilding.
I think Ainge has been doing a good job accumulating assets but I don't like all his moves. I think Ainge should have bought Prince out immediately rather than playing him and eventually trading him for Jerebko and Datome. I probably would have also traded Bass after Rondo and Green were traded. I would definitely be looking to trade Turner.