I don't think Horford has played with a good pg. Bibby is a good shooter. In Chicago with Paul and the running game, Horford will flourish like West and healthy Chandler did.
Again, I think including Tyson Chandler is mixing apples and oranges.
I see Horford much closer as a player to Chandler than David West in terms of their respective skill sets. David West is a dynamic offensive talent who doesn't rebound as well as he should and who's a (maybe) good defender.
Chandler (and Horford) are very-good-to-great defenders & rebounders who can give you 10-15 points a night.
West *has* flourished offensively playing with CP3, but I would argue that's because he's a better offensive player (i.e. if he was playing with, say, Mike Bibby or Hinrich he'd still get 16-19 ppg off his talent).
On the other hand, Chandler's average with CHI was 7.1 ppg and 10.2 ppg with NOR; He's not scored more than 22 points in a game with CP3 getting him the ball.
If you want to argue Horford scores 14 ppg instead of 11 ppg playing with CP3, fine. But generally speaking, leopards don't change their spots. Horford might improve/flourish, but he's not going to *become* David West.