You want to look at the last 5 games of the series then look at these stats:
James Harden -48 I guess he needs to go
Clint Capela -58 Definitely don't pay that guy
Eric Gordon -55 Time to blow up the entire team
Guess what, in the last 5 games of the series the Warriors outscored the Rockets by 72 points. Of course all of the stats will be a bloodbath for the Rockets.
Ariza was plus 26 in game 2 against the Warriors and a big reason they got that win.
If you think Carmelo is a better player and fit than Ariza was then I don't know what to tell you.