That proposed trade for Paul George is just ridiculous if you compare it to the Kevin Love for Wiggins/Bennett trade two years ago.
First, Cleveland had very little leverage as LeBron had basically mandated to the Cavs' FO "go get Love." So to give up the #1 pick in the draft and a bust (Bennett had very little appeal) for a 25-yr old Love was actually much less than what the Pacers/Bulls have been asking.
George is about to turn 27, has just come off a horrific injury, and has given no indication (unlike Love three years ago) that he'd resign with the team trading for him.
Once you know what that Nets' 2017 draft pick will be (is it #1 or #4?) things will become much clearer for a team such as Indiana in weighing offers. Was Love in 2014 better than George in 2017? That's debatable but I'd say they are pretty close in "star power."
By passing on a trade now, Ainge could potentially get George for much less than was rumored to be required by Bird. Possibly the 2017 Nets pick (let's say it's the #2 pick) and either Avery Bradley or Smart (depending on who Bird likes), plus filler. I'd even venture to say that Danny wouldn't give up the 2017 Nets' pick plus Brown because of Brown's all around potential.
Otherwise, Bird risks losing George to the Lakers for nothing.