Mavs get a PG with Simons, but don't have to give up significant draft capital because he's on an expiring contract. They give up Gafford's team friendly deal, but also save on Klay's $17.5M next year.

Bulls trade Vucevic for a much younger C in Gafford who is on a team friendly contract for 3 more years. They have to absorb Klay's contract to make the swap at C. Bulls still remain under the luxury tax.

Celtics trade Simons for Vucevic to save an additional $6.1M salary cap (more in luxury tax) and maintain cap flexiblity next year since its an expiring for an expiring deal.

No 1st round picks traded, but 2nd round picks can be negotiated to close the deal.

Bulls also have other PG (Jevon Carter, Coby White, Tre Jones) that Mavs can pursue in a direct trade.