He sees the truth, just like most people. Hard not to in that pairing's case, early in the year.
The problem is he's so attached to his guys that he's willing to accept bad results for prolonged periods now, to give the players he favors more time to recover. He's worried about their feelings, and his relationship with them.
The urgency to correct problems he used to have when he came here is gone, unless you're players he values less, who get short leashes.
By the time he finally broke them up, a lot of damage was done. His hesitancy probably cost him a playoff spot.