Yeah, the coaches also have no idea where Carey is picking. Some of the crystal balls to Duke have come with a disclaimer that it's a guess. It's 50-50 and it we don't land him Stewart is likely heading here.
Between the 2, I think Carey is way better right now, he's more polished and is a scorer who can score from all over the court, not just the post. Stewart is more of an energy guy, is a better defender, but doesn't have the offensive game Carey has.
Carey is the type of post player you win National Titles with, he's basically unstoppable inside 15 feet. Stewart is really good too, but just not that much of an impact on offense.
Vernon Carey compares to Joel Embid in the NBA. Stewart is more like a Miles Turner (Pacers Center).