I've mentioned this before, but even when watching prospects on defense closely it's hard to know how much to take way from it. Just playing a little devil's advocate, but the talent level/coaching level is so low at the NCAA level that pretty much all of these guys are "lockdown" at the college level to some extent. And of course, I think the eye test favors things that are most conspicuous, but not necessarily the most important to overall defensive value. There's honestly not a huge difference in good/bad defenders in terms of their 1v1 on ball defense. I think Ace is a better defensive prospect than the two guys drafted around him, for example, but the film will show Kon and Tre locking down most guys at the NCAA level as well.
People are going to hate this, but I think numbers do a relatively good job of the skillsets/attributes needed to succeed at the NBA level. Defense in the NBA level is very much about what goes on between the ears and those decisions rarely present themselves at the college level. The NBA is a 5v5 game, whereas as college is more like a 3v5 game played in a phone booth lol. But the numbers can show who can transition to the next level. The event creation (stupid name I know) numbers are very meaningful indicators IMO. And Ace is also pretty good on paper as a defender which is a stronger reflection of his potential than staying in front of Prince Aligbe.
Ace will do a lot of different things on both ends, but if you can really teach him to be a secondary backline defender that would be awesome. If not, I think he will be a fine, switchable on ball defender.
