I think the #10 pick in this draft is more valuable than the SAC pick(top 1 protected) next year. Regardless of whether you would rather save the roster spot or something this year, the further a pick is from actually conveying into a player, the less valuable it is. And there are a lot of uncertainties with the pick this far out. We don't know what the Kings will do in free agency or the draft. They might do something stupid like trade some young guys for vets so they can try to make the playoffs because they don't have their pick this year. It is the Sacremento Kings for God's sake. Plus there's the new lottery reform, which makes the draft an even bigger crapshoot.
Look at the potential prospects that are going to be at #10. 2 of these guys will be available. Trae Young, Jaren Jackson, Wendell Carter, Collin Sexton, Kevin Knox, Miles Bridges, and Mikal Bridges. Those are solid prospects. It's early, but the 2019 draft doesn't look nearly as strong as this one.