As to your question, I don't know.

As to the fight between Campbell and Casamayor, it's not gonna happen. I think they bid a low amount, if they won they would have set different fights with each fighter, then made this fight if both won. I don't think the bidding of this fight has anything to do with your question. From what I have heard, they are setting a fight between Casamayor and Juan Diaz. Both GBP fighters and probably a more marketable fight.

Casamayor feels he beat Campbell and doesn't want to fight him again unless there is a big purse.

I think they do ok as building up fighters. They have more up and coming guys than Top Rank. It's kind of like trainers. Freddy Roach isn't training beginners and bringing them through the amateurs. He gets pros that have already established themselves. I think DKP and GBP and Top Rank are major league promoters. You pay your dues and work your way up with local promoters before they would even hear of you.