2018: Jalen Brunson over Lonnie Walker IV with the 18th pick
With the Spurs drafting Murray and White in 2016 and 2017, we'll skip over them considering that they were both great picks. However, Lonnie Walker, at 18, perhaps wasn't. Walker never quite put it together in San Antonio, despite his physical tools and skills. To his credit, he went on to become a decent NBA player, but he should have been better.
Additionally, there were several good players taken after him, including Jalen Brunson, who was taken 33rd overall in the 2018 NBA draft. Brunson started his career in Dallas, where he quickly exceeded expectations while playing alongside superstar Luka Doncic. After four seasons, he left in free agency and signed with the New York Knicks, where he was a borderline all-star after averaging 24 points and 6.2 assists per game.
With surprisingly few point guard options in this re-draft, Brunson is a no-brainer inclusion on this hypothetical Spurs team. In this scenario, Brunson would play behind Murray in the second unit but could close games for the team, giving the Spurs a wealth of clutch playmakers. Imagine a closing lineup consisting of Brunson, Murray, Butler, Leonard, and Jokic, Had the Spurs taken him instead of Walker, they would have definitely gotten more out of the 18th pick that year, but they have recovered nicely since then.