This would definitely make the Celtics a worse team. Frankly, I can’t see a good reason to add an albatross contract like his, especially because he begins the season at age 30.
To be sure, he has some skills to recommend him,but this would be a step backwards.
He’s an outstanding jumpshooter, including from long midrange, which is rare, and a great asset in today’s game. Good finisher, too, but he doesn’t get to the line much - Marcus Smart’s ftr is twice what McCollum’s was this season, though they’re both grade-A FT shooters. Similar Ast%s, but is anyone going to claim that CJ does as much to organize an offense as Brother Marcus? I didn’t think so. On the defensive end there’s no contest; good hands and quickness but he’s 190 and not in hailing distance of Smart, and he’s a lot less versatile/switchable. I’d pass on a straight-up swap, let alone with the other assets that you’re proposing.
I wouldn’t trade him straight up for Nesmith either. Aaron is 21 with good length and spring and defensive instincts. BIG age and salary difference. Nesmith shot .392 from 3 in the last four months of his rookie season, shot over league average for the whole season and over .500 from 2. He’s got a repertoire of shots off the dribble, including the all-important 8-10 footers over rim-protectors. His blossoming ability to guard wings and his emerging shooting make him a perfect complement to The Two Jays going forward.
CJ is cripplingly expensive for what he does, and he’ll be on the wrong side of 30 next year. It’s safe to say that nothing like this deal is going to happen.