Eff all that. The goal shouldn't be to try to get a designated shooter to make the broken perimeter players the Spurs currently have work. There's no way they should go into next year with the plan to be to run White, Murray, Johnson and Poeltl. That's barely a more functional unit than the one this year. I have nothing against any player in the draft at this point, so this isn't me not being okay with Kispert. But even with him, the Spurs need to replace one of their perimeter starters with a guy like Vassell. Honestly, the team needs to be capable to replacing two this off-season, whether it's because Vassell takes a leap, the team drafts a player or they use some of their cap space to drag away some free agents.
IF Murray, White and/or Johnson prove themselves as starters in camp, sure keep them. But don't have them go basically unopposed. Developing them isn't the team's priority anymore, certainly not to the point where another young player like Bouknight can't develop because a bunch of meh guys keep taking turns running into defenses and burping up bad possessions. Basically, the Spurs shouldn't draft with roster fit in mind. They have plenty of cap space to worry about that. They're going to have to just take who they think will be the best player, whether that be a role-player or a potential star who'd require a complete reworking of his supporting cast to develop.
I also think that the Spurs should be more willing than every to trade some of their "core" for future value. They no longer have a leg to stand on when it comes to them "winning now", so using looking to make a deal with White, Murray and/or Poeltl makes a ton of sense. Moving any of those guys also opens up a spot for a shooter who'd make it easier to draft a guy who needs space.