Spurs take on Giannis for Vassel, Johnson, Castle, 3 FRP, & 2 SRP.
This is the perfect plan for the Spurs, getting Giannis will immediately make them Finals Contenders for 2026, prob the next best team behind OKC in the West. I don't see the Spurs trading the #2 pick in this year's draft to the Bucks bc they would still get this year's ROY, Castle. They could use that pick to draft Dylan Harper, a combo guard that can slide to the two alongside Fox. They should also try to bring back CP3 for veteran leadership on the team.
For the Bucks perspective, trading Giannis is a different or a new chapter for the organization as well as the fans. One way to start is by building around Castle and the picks you'll acquire from Giannis. This would be perfect for the Bucks, especially when you get solid starters like Vassel & Johnson. They should try to bring back Lopez & Portis, bc you can't afford to lose them for nothing.
Spurs: PG - Fox SG - Harper SF - Sochan PF - Antetokounmpo C - Wembanyama B - CP3, Branham, Barnes, etc.
Bucks: PG - Lillard(?) SG - Vassel SF - Johnson PF - Kuzma C - Lopez B - Trent Jr, Portis, Green, KPJ