One of Daryl Morey's biggest mistakes was letting Luc and Ariza go. Outside of PJ Tucker, the Rockets have no other two way forward. If you can't keep Ariza due to money, then they should have tried to keep Luc as his replacement in the starting lineup. Not the likes of James Ennis.
What Morey was thinking idk unless the owner was being cheap. Jimmy Butler was there only hope possibly and their defensive coordinator coach coming back. If the defensive coach comes back and the defense is elite all of a sudden, Dantoni needs to personally give him his coach of the year award.
Around this time last year, the defense was ranked about the same (I think 17 or 18) as it is right now. The major difference was the Rockets incredibly efficient offense. This year they are dead to last and now this mediocre/shytty defense at this point in the year is not going to work if your offense is trash.
Imagine if those two moves changed the Rockets from a championship contender into a non-playoff team.