It all depends on the circumstances.
First, I am not sold on Drummond not being a dog. So, I could see a scenario where Dumars just wants to sell high on Drummond before he is exposed for what he is.
But beyond that, if Detroit were to consider trading Drummond (or Monroe) for Rondo, it wouldn't be because they saw equal value. It would be because Dumars has been given the directive to win NOW, and Rondo is the most talented player that is a realistic get, who fills a need...and Dumars wants to keep his job.
These type of deals happen all the time in the NBA. A GM gets desperate, and gives up more than market value in order to pry a player away, because their ownership needs to sell some tickets.
Realistically, I don't see them keeping Monroe, Drummond, and Smith together in the longrun. Its just not a good fit. And right now might be the time to sell, before Monroe gets any closer to his payday, or Drummond gets any more exposed.
Flip one of them for one of the most dynamic and popular players in the league, who is friends with your new PF, and who also plays with an edge that Dumars has always been partial to in players. And try to win now.
I don't think it is likely. But I think it is a possible scenario.