I don't know who is "better" defensively, TBH. My point was just that the Rockets didn't get better on defense, over this trade.
Here's something I haven't seen anyone else talk about:
The Rockets are still going to have to fill a roster. They traded two guys who played 2,000 minutes each last season, for one guy who played 1,900 minutes. They are going to have to fill in a load of minutes, and a lot of them will almost certainly be with player(s) who aren't as good as those two. So no matter what they gained by adding Paul, they're going to give some back unless they make another deal somewhere.