I'm on board with this as long as Masai goes and gets some shooting.
Fwiw, I'm going to assume that the 3rd team is the Lakers. The Lakers have been attached to the Spurs with Westbrick rumours recently and this works under the cap:
To SAS: Westbrick and all the Lakers future 1sts
To LAL: Gary Trent Jr, Doug McDermott, Gallinari
To TOR: Jakob Poeltl, Josh Richardson
Why SAS does it? Clears out some of next year's salary (if they get Vic, they can immediately sign a max player to compliment him and the kids) and loads them up on future Lakers 1sts that will be post Lebron era and probably top 5-10 picks.
Why do the Lakers do it? Gets them some legit shooting and scoring depth as well as a young piece like Gary that they're willing to go deep into the tax to use their bird rights on.
and the Raptors? So...we kind of need a centre, and Poeltl is a really good modern rim runner. Does everything well that we're missing. Rebounds, defends the rim, generates offence without needing touches. He's expiring, but Pascal is legit his BFF and he knows the city and program well. A pretty easy re sign and the centre market is always soft, so he's probably looking at half the cap hit Gary is for 2-3x the impact. Also...Josh Richardson is the role player version of Gary. We lose no shooting in this scenario, but shift our "Gary" to the bench (where he's belonged imo). Expiring as well, so if he's a bad fit down the stretch just don't exercise your cap hold on him and let him hit free agency. Not a bad guy to have bird rights on though, won't be expensive to keep and is a solid 3pt shooter as a bench guard.