First of all, Harden leaves Philly. If Atlanta wants to end his relationship with Trae Young and finally get rid of Collins, they would be getting a good scorer on Harris, a future star on Maxey and some role players to build aruound DeJounte. Philadelphia ends his roster by signing some free agents: Caris LeVert (he doesn´t have enough minutes at Cleveland with Garland and Mitchell) and Seth Curry (comeback to the Sixers; he is out of the rotation in Brooklyn). Them both would bring some scoring from the bench; the Sixers would be an elite three-point shoot team, as it have been that past season.
Philadelphia would start the 2023/24 season with this roster:
PG - Young - LeVert.
SG - Melton - Curry.
SF - Bey - Niang.
PF - Tucker - Collins.
C - Embiid - Reed.