I would absolutely be fine dangling Simons + a future first round pick + 1-2 second rounders for any of Claxton, Zubac or Vucevic.
Yeah, neither of them are superstar bigs but that's fine. Realistically, I don't think you're going to get much better than these guys over the next year in trades or FA, and that's okay. We don't need a superstar, just a very solid to above average starting center who can be productive and gives the team more size. Queta would be an awesome 6th or 7th man as he continues to improve.
Then you can definitely contend with PP, White, Jaylen, Tatum, the center you acquire, and a very solid bench of Queta, Hauser, Walsh, Hugo, and maybe 1-2 of Minott/Baylor/Amari in the mix.
I fully understand the arguments that we may not technically need another center, but if you literally have an injury to someone like Queta then you're frontcourt is already kind of cooked. We had Horford for a handful of years as a very nice backup to Porzingis and even Timelord (or Horford starting, Timelord backup) while Kornet was a solid 3rd big. Garza is okay as a 4th big, not much more than that. They absolutely still need a starting center (or very good backup) even after Tatum comes back for beyond 2026.