How many double digit assist games does McCollum have? Shooting is not the only part of the game that matters. Trey has had a 15 assist night therefore CJ has never had a game like Trey. Neither that fact or yours makes either better or worse than the other. AS I point out they have differing skillsets.
Again this isn't a Trey vs CJ discussion. This started because someone(I believe you) said imagine if McCollum was on this team. My point was he's not going to average 23 even in the first 4-5 games because he has to share shot attempts with Favors, Hayward, Burks, Hood, and to a lesser degree Gobert,Booker, Ingles and Neto. He that's not something he has to worry about with portland. His averages aren't better than Trey's yet Trey isn't getting those shots what makes you think McCollum gets those shots this season? The idea is he's a better shooter but the stats don't agree with that.
Trey doesn't have the same freedom that McCollum has this year, again not sure how that's debatable. Trey's not getting the mins or shot attempts. Not a knock on CJ he's doing well with the freedom, but it's 5 games.
As far as last second shots that's an actual attempt in the half court and while more difficult than shooting with time it's not nearly on par with a half court heave. Please don't tell me that's the case you are trying to make?