It couldn't happen until September 12th, but Rondo, Wallace and Crawford for Charlie V's expiring deal, Stuckey's expiring deal, Brandon Knight and Andre Drummond works money-wise.
Boston would be giving up a long time all star for a big man prospect who might never be a great player, a decent young PG, and expiring deals. Boston also gets value from getting out from under Wallace's three year deal.
I personally don't want to see Rondo traded, but I do see the logic of this kind of move. It would pretty much guarantee a high draft pick this summer in a loaded draft, and if young Drummond develops, he could be a very good big.
For Detroit, they already have a solid low post player in Monroe, and playing Monroe, Drummond, and Smith together probably isn't going to work, because none of them can shoot. The could roll out a team that would be very good defensively and should be able to put points on the board.