But really, why would the Bucks trade Middleton to the Mavs? If they keep Giannis, they will only trade Middleton for a player, that makes them better, which Dallas can't (won't? - KP is of the table imo) give them. Just cap space is not all that useful to a small market team like the Bucks. If Giannis leaves, then they'll want young players with upside and/or picks for Middleton. Again something the Mavs can't really provide.
Middleton is signed on for 4 more years. no one is giving them value for Middleton as a favor to Milwaukee. They can probably get Tobias Harris from Philly, but that wont move the needle either. Giannis stays if the Bucks can convince him there will be major roster changes that will happen. Keeping Middleton there is like doing exactly the same thing and expecting a different result. Trading THJ's expiring contract + Powell + 18 for Middleton gives Milwaukee a max slot for 2021. Now they can use that to get more players that fit around Giannis. Mind you, there is no other team that is willing to give up 2021 cap space just to help the Bucks. That team is locked in for years as Lopez, Bledsoe and Middleton are on fresh new contracts. Either they give up someone for flexibility or they stay locked in with the same roster expecting a different result.
Dallas does that if Giannis decides to stay. Im not liking Dallas' chances for Giannis either. Pat Riley for Miami, Jerry West for the Clippers, and even Lacob for Golden State are just waiting like vultures waiting for Giannis to declare his departure. Donnie Nelson doesnt stand a chance against RIley or West. He looks like an amateur compared to those two. Plus they have south beach and LA weather going for them. Middleton is a really good player to play the 3rd star role behind Luka and KP. Can play off ball, shoot the 3 and defend well. You're adding a 20ppg scorer to the team, I dont see that as a bad thing, especially if the other options in 2021 (without Giannis) are Oladipo and Gobert. I'd take Middleton.