Ehh, it's hard to say who has the higher ceiling tbh. Sexton is aggressive and athletic, great at creating his own shot,and really does have a pitbull mentality which is what the Knicks need, but he's also a below average shooter and can't really hit the three, isn't a natural facilitator, doesn't have good vision for a pg, forces bad passes, is turnover prone, and doesn't really move without the ball. He'll only be effective as a high usage guard on this level imo, but he'll be the guy who phases other players out at times, and force bad shots at the rim all day long. If he gets drafted he'll need a guy like Frank next to him, but he seems like a poor man's Eric Bledsoe to me; an average player really. If he can learn to be active off of the ball and become a good shooter, then he'll be a very good player, but it's hard to trust guys who have mechanical issues to improve even if they're slight; it's HARD to overcome years of bad habits and muscle memory, and that's true in general, not just in regards to basketball.
Trae is harder to project because of the night and day difference between the first and second half of season. He reminds me of Trey Burke to keep it succinct, but with a better 3 point shot, sloppier handles, worse defense, and a lightning quick release. If he can rein things in and make shots with the consistency that he did earlier last year, the he'll easily be the better offensive player of the two;hell if he can do that then I'll agree with you and add that he can be an all-star, but that kind of shooting doesn't seem realistically sustainable at this level(unless you're Steph Curry). The questions come on the defensive side though, he'll probably be a god awful defender his whole career because of his height and his frame, and he'll get abused every night on defense through switches and isolations. If he be at least Trey levels of bad then you can live with it. He has the potential to overachieve, but his bust potential is crazy high too. He'll need good to great defenders all around him to get the most of out of him
Mikal has average explosiveness, but he's a fluid athlete. He won't be able to create shots for himself at this level (at least for a season or two)because his handles are shaky. He looks a like a guy can maneuver well around screens and get open shots for himself off of the ball though, so he won't be limited to a spot up shooter, he makes good reads on the offensive side, boring but won't kill you with bad plays. Most of his value comes from the defensive side, if he gets stronger then he'll be a guy who can switch from 1-4 and be a deterrent, and being able to switch most positions is insanely valuable nowadays, and is a very big reason why a team like the Celtics is overachieving in the playoffs. He doesn't have the flash to make him an all-star, but can have the impact of one if you factor in both sides and he can make open 3's with consistency. The fact that he's gotten so much better over the last 3 college seasons, and now is a lottery pick when he wasn't projected to be an nba level player last year, suggests he has a sneaky high ceiling.So who knows, maybe he'll become a way better offensive player than everyone suggests? but I've already read a few articles today suggesting he may end up a top 5 pick, so he might not even be there at 9 for the Knicks to pick, which just goes to show you that nowadays, 3 and D>>>>>> good isolation player, they're easier to build with and around. You have to be at least a great iso in order to make it a debate.