I'm not saying that it's not possible for either of them to be allstars or better players someday. But i'm saying in real life, teams don't just trade their young, loyal, all-star PG on a friendly deal for a guy in a draft with no consensus #1. it is way more probable that neither of them ever become as good as DG. i understand wanting to take risks and swing for the fence, but it's just not realistic and considering how pro-Spurs DJ is, trading him for a pick would look really bad for any potential FA targets. Imo it's just one of those things that's so unrealistic and un-Spurslike that it's not worth discussing
Besides, almost every draft there's someone taken after the top 5 picks that ends up being better than some of the dudes in the top 5. 2020 you had Haliburton/Bane/Maxey, 2019 you have Keldon/Poole/Herro, 2018 Bridges/Bridges/SGA, etc.