I'm sensing an awful hate-on for Rockhold. It seems to be clouding your judgement, not only of Luke, also of Costa. He's hardly the worst ranked middleweight at the moment. He has been solid in his last few outings. A fight between these two would be a great determiner of who gets the next contenders fight.
But don't you agree that Costa is the easiest fight for him? Philippou is mainly a stand-up guy with no particular skills on the ground, and his TDD isn't anything special either. Rockhold will come in, take him down, keep him there for 3 rounds, that's it. I'm thinking that, if Belfort wins in an impressive fassion, Luke and him could fight for NR 1. contenders spot.