Here's an idea. I think the Pelicans are one of the most poorly run franchises in the NBA, but I think they may try to make win-now moves to get back in the playoffs.
Celtics get: Giannis and Murphy
Bucks get: Murray, Poole, their own 2027 1st swap rights back from the Pels, picks from the Cs, and a young prospect from the Pelicans (Missi, Hawkins, or Matkovic)
Pelicans get: Brown, White
Pelicans move forward with a core of White-Brown-Jones-Queen-Zion, with Fears, Bey, Looney off the bench. I think that's a team that can push for the playoffs, and the Pelicans don't have to give up any of the core players to make this trade happen.
Bucks get their own 2027 swap rights back from the Pelicans, which is the big win here. They control their pick in next year's draft. They get picks from the Cs. They also get Murray as a rehab project that could be flipped to a playoff team at the deadline. I'm guessing they would want 1-2 more young prospects (Gonzalez, Fears, Baylor, Hawkins), but I think they get what they want and that does not become a hangup to the deal.
Celtic core is Giannis-Queta-Tatum-Murphy-Pritchard, with Hauser, Hugo, Baylor, Garza off the bench. That teams needs some more vets to fill out the roster, especially a stretch 5 that can defend the rim, but it's an immediate contender.