3.) Graham, Vassell, Johnson, McDermott, and Wembanyama
In closing lineups, the Spurs will likely play Wembanyama at center and add shooting around him. One way would be to insert Devonte Graham and Doug McDermott, along with Vassell and Johnson, into the game to play alongside Wembanyama. That offensive lineup could be hard to stop with two shooters surrounding the Spurs' three best players.
That would be especially true for opposing teams that don't have a player who can guard Wemby one-on-one. Who would they leave open? Forcing teams to make tough decisions like that should allow the Spurs to generate good shots late in the half.
Of course, Graham and McDermott aren't good defenders, and teams will likely exploit them on the other end of the floor. But with Wembanyama able to cover a lot of ground and challenge shots, he could put a lid on the rim, making it much tougher for teams to score in the paint.
Making it more difficult for teams to score in the half-court would make it harder for them to keep up with the Spurs in this lineup. Even then, this offensive lineup probably won't work every game, but if San Antonio is down late or struggling to score in general, then it makes sense to try this 5-man unit.