DISCLAIMER: I had this trade thought up with the players and everything before ESPN came out with their version that was only picks.

This trade only makes sense if Nico, and the Dallas FO, think the gap between Flagg and Harper isn't that large and is comparable to, in totality, the #14 pick, getting their 2030 swap back, getting in on the ATL pick swap next year, and the gap between vassell and klay thompson (the 2nds are just sweeteners).

As it stands, while both teams are more than happy to choose where they're at, theres obviously current roster/fit issues with dallas picking flagg and SA picking harper.

Flagg is undoubtedly a generational prospect, but a claim could be made harper is more ready to contribute right now on offense (defense is a different argument). Additionally, it's difficult to build a competent team without elite guard play, as evidenced by the conference finals, and theres no guarantee flagg becomes an all around team creator and doesnt top out at elite individual creator at the forward position, which is more expected from someone his size. not to mention, if taken by dallas he'd most likely play slightly out of position at the 3 and be forced more onto the perimeter than is ideal. Harper would immediately slot in as the lead guard since kyrie is out and dallas really doesnt have any other viable options. even when kyrie comes back, harper has the positional size to play the 1 or 2 with kyrie. upgrading from klay to vassell also gives dallas immediate help in more creation and playmaking while also being a piece that could grow with harper as kyrie and AD age. not to mention getting a shot at #14, getting draft capital they should've gotten in the luka trade, and getting off caleb martin's contract early.

Harper is an amazing prospect at lead guard, but SA drafted castle last year (who showed he isn't just a complimentary guard/wing but actually a competent creator able to drive offense) and traded for fox. while i do think harper's offensive upside is higher than castles, castles defense does bridge that gap in overall potential, and i think harper is ultimately just a younger fox in the long run. while all 3 can play together because of castles and harpers size, in the long run youre going to reduce touches between the 3 of them to make it work, not to mention vassell would also start playing out of position at the 3 to let the other three guys take up the guard minutes. Most likely the #14 pick, ATL's pick next year, and the second rounders would be used trying to upgrade the forward position whether directly through the draft or in a trade. itd make more sense to just combine those assets and the #2 to go directly for the guy who makes sense as a do it all forward that'd fit next to wemby if thats what those picks would be used for anyway. flagg could slowly grow into his offense on a team that has wemby, fox, and castle, while also playing more to his strengths at the 4 and with a stretch 5 in wemby able to open up the court. klay gives SA a reliable shooter at the 2 who can play with either fox or castle, and getting flagg allows SA to evaluate some of its less well rounded wings to see if they can use them to get better help around the core of flagg, wemby, castle, and fox.