I don’t know if it makes them “significantly” better. One area it will help is that it takes the ball out of Harden’s hands some of the time. At the end of that Spurs series, Harden looked knackered and just wanted to go home. Maybe Harden won’t be as tired at the end of games if he doesn’t have to run the offense most of the time.
The 2nd and maybe more important reason is that Morey seems to be looking to build a super team. He really is trying to get Paul George with spare parts. Now I know it’s a long shot, but if he managed to do that, all of a sudden you’re looking at Harden, CP3, and PG. That gets them serious consideration if Melo gets bought out. Even without PG, it’s a bit easier selling players on comin to play with CP3 and Harden, instead of just one star. I know it’s a lot of ifs and it seems far fetched and crazy, but if we know anything about Morey, it’s that nothing seems too crazy or outlandish for him. You best believe he’s gonna try