Spurs don't really need Thad Young based on what they're doing and taking a chance on developing Jalen Smith makes sense for them plus any picks are always welcome. Dario Saric should be moveable for assets post-injury too.

Suns get a jack-of-all-trades/glue-guy that instantly improves their rebounding and interior defense, weaknesses that were exploited by Giannis and the bucks playing big in the finals. Saric will likely sit all season and I doubt Jalen Smith can be a rotational guy come the 2022 playoffs even if he does improve.

Regarding the trade, I reckon both teams wouldn't feel like they've undersold/overpaid with this package - and end of the day Suns need to make moves to improve their roster again or else they risk falling behind a healthy Lakers, Nuggets (if Murray returns) and Jazz