The Spurs will have their board, and perhaps on that board, Harper isn't that far about a guy like Tre Johnson. Maybe he's not higher at all. The goal of the draft is to be right, not to align with consensus. It's hard to see another guy being a better prospect than Harper from what I've read, and we know that when this front office zags, they don't always find the better option. But they still have to go with what they think is best, and that means they should be willing to make a trade if necessary. But to be honest, I have this pick as the clear second spot on the "untouchable" rankings behind Wemby. The Spurs need to ace this draft given how unlikely it was for them to be in this position. I don't think they should consider trading the pick for a vet, and if they move down, it should only be because they think the guy they're drafted at the lower pick is going to be a top-three player from this class.
I don't think the Spurs need to make a trade at this time. But if they did want to go star hunting, my max offer would be Castle, Sochan, Vassell, 2026, 2028 and 2030. That's enough salary to match up to $54.8 Million in salary, or pretty much any contract in the league. Give the swap options on those picks, I don't think there's a package out there that is more valuable outside of Houston or OKC cutting deep into their quick. I don't even think there's a good target for that full package. If you swap out Vassell for Branham, you might have a Jaren Jackson Jr. package. The issue is his makes so little that it'd be hard to imagine he'd sign an extension. The defense would be so ridiculous that it would make a Jackson/Wembanyama front court worth a lot. But the risk of Jackson walking for nothing would be too great to wager that much flexibility and draft capital on. Any other feasible trade that isn't Giannis shouldn't require the Spurs to move Castle or 2.