slamtheking and CsBanner18:
You both make good points. I have a few responses, though.
First, I constructed the trade proposals to reflect the maximum I would give up for the two players involved. That seems to me the only way a deal would get done. Obviously, I would prefer to keep Crowder (and Bradley and the picks for that matter), but you've got to give to get. I don't think the Celtics should let the prospect of losing Crowder, who is a very good player, prevent them from obtaining Griffin, who not that long ago was a top-5 MVP candidate and is still young-ish.
Second, although I agree that Crowder and Bradley have been the two biggest contributors to the Celtics #2 ranked defense, I credit the Celtics' success on that end of the floor more to Stevens' system. I also believe that Smart will make huge leaps forward in his defensive impact in the next couple years, which will mitigate against the loss of Bradley, in particular. Moreover, although Griffin and Hayward might not be at the same level, they are still plus defenders.
Third, the whole point of collecting trade assets is to use them for something like this. Even though the Celtics wouldn't have the same flexibility moving forward, they have to find a way to consolidate. And even under this scenario, the Celtics still get the potential infusion of high-end talent from the 2017 and 2018 Nets picks, which could be quite high.
Fourth, I expect Griffin and Hayward, along with IT4 and Smart, would draw the interest of free agents looking to win. For example, if KD is looking for a new team this summer, it's hard to imagine many better landing spots for him to earn a ring (without joining Steph's or Lebron's teams) than the Celtics. Other upper tier players like Horford might also be gett-able under this scenario.
Bottom line: I agree it is a lot to give up. In fact, it is the most I would give up. But it's hard to turn 10 dimes into a dollar. And high end talent wins championships. So I would do it.