Whenever you use 1 game as an argument you have no ground to stand on.
Sexton sure has had an impact but it was more about having 2 functional units that had built chemistry and both of which could win or compete in their minutes.
Post Simone trade we have been way worse than the Pistons who were near historically bad up to that point. And that is with us playing 5 at home and 2 on the road, against bubble teams (Lakers, GSW, Hawks), Suns and 2 bad teams (1 of which we lost to, at home).
With Simone, Pistons have the same record as we do (1-6) with superior net rating (-6.4 vs our -9.7) but they have played: @Clippers, @Pacers, @Suns, @Lakers, @Knicks, @Bulls and their only home game was against the Magic.