Shump for Delly is a good deal for us. Maybe even a good deal for Milwaukee too.
If Delly really is available for trade - which, by the way, given how deadly the Brogdon-Delly-Giannis pick-and-roll has been the last month, I don't buy for a second - then a Shump trade may help Milwaukee... It depends what they want.
On one end, Middleton has been outstanding for them, losing your backup PG for a worse defender while your starting PG is just a sophomore is a tough pill to swallow (as we saw with the Cavs this year), Delly has become vital when they run Giannis as a role man, and even more vital when Giannis is the ball handler and Delly sets the screen, and Delly serves as a champion, veteran presence for an otherwise young team.
On the other hand, Milwaukee has two ball handlers in Brogdon and Giannis, they could use some more length off the bench, and while fun and great, Delly is not irreplaceable given proper planning.
Ultimately, I don't see the Bucks trading Delly until the 2018 offseason. He's too valuable while this young team is growing. Additionally, if they did decide to trade him, I think there would be better offers on the table.
If the Cavs want to trade Shump then they should look at a team like OKC - who is about to lose Roberson - for a potential deal. It's possible that, if the Thunder decide to move Kanter for a second option to Russ, the Cavs can squeeze in as a third team with Shump.
I just don't see any scenario where the Cavs get a player back of Delly's caliber for Shump... From what I've gathered, the entire league is really low on Iman, and they don't like his contract. I think we'd be lucky if we could dump him for a draft pick.