The trade Ainge did before the Big 3 era for the draft rights of Rondo was a good one. However, you are correct in that Ainge hasn't done much trading since the C's were built to be a Championship contender. Other than the Perk trade, and reviewing the link you put here, Ainge's only other quasi-major trade was to get Robinson from House.
Has Danny had any motive to trade and ruin the Chemistry of a Championship contender other than Perkins leaving for more $$$ this year and getting nothing in return for him had he not Traded Perkins?
Clearly with the David West and Chris Paul Rumors this off-season, Danny has been a lot more aggressive at trying to trade to upgrade the talent of the team because he knows, along with most people, that the C's need a talent upgrade to be a leading Championship contender now. He missed, sure, but it's better than sitting on his butt, collecting his pay-checks and counting his cash.
All his trades did not lead up to KG & RA anticipation, but the one that got Theo Ratliff's expiring contract did which is why he had to give up a Draft Pick. Wasn't that Brandon Roy who made a few All-Star teams but also had bad knees and is forced to retire early? A lot of us C's fans, including me, did not see the method to his madness at the time, but in hindsight, a good portion of his trades make sense.
I'm not trying to say Danny is perfect, not trying to say that Danny's a great trader or anything, just want to point out that there was a strategy or a process to get RA & KG and that starts with good drafting and acquiring assets.
Quantity + Potential (Young Players that can improve and play a lot of years) for Quality (KG + RA)
Al Jefferson + Gomes + Draft Picks + Expiring Contract + The Rest for KG
D. West + Wally for RA