I mean, "sizeable potential" to be something like you expect them to improve by a tier (rotation player/role-player) or two (elite role-player/key rotation player/average starter), MAYBE three (high end-starter/lower-level star) if everything goes right. But you don't see a star or centerpiece. If you did, they'd be in the "blue-chip" category. I did say in there that the Spurs don't have a "blue-chip prospect", so I didn't mean that those guys had discernable potential to be elite. I think if they reached Murray's talent but with skills better suited for the modern NBA that they'd be home-run picks. There are only so many fringe All-Stars in the league. That's at worst top-75 placing. That's above-average starter, if not lower-tier star. I've been trying to guess too much about "ceilings", but if you told me that an optimistic but still somewhat possible roadmap for each of those guys takes them to being top 2-3 players on a generic team, I'd actually feel pretty good. You can put those guys around a star. You can trade those guys for pieces.
As far as how other teams view those players, I think they aren't yet willing to pay for Johnson what the Spurs would need to get to trade him (and by the time they are willing, the Spurs would want even more), they value Poeltl but want the Spurs to be reasonable. Vassell is a prospect who isn't interesting yet. Sochan and Primo are likely in the same category because they're willing to defer to the Spurs and will assume SA won't part with them. Branham and Wesley are probably too close to their own prospects to worry about. Any of the other young ones are flotsam. An FO might like one or two of those guys as fliers in the right cir stance, but they would rather add them as two-ways or 10-days later on.