Let these fighters fight at their own will, it seems that they're not having their own willingness to do so. If they're confident to take the match then so be it, no aggressive offer should be given to any one of them. Once a boxer find a good mood and his capacity for fighting his potential opponent would technically be drawn over by his power, I guess with no hesitation their fight would commence successfully.
But remember that they work with promoters, networks and world governing bodies. So you can't just go ask and fight anyone in the ring. There has to be some kind of model here so that everyone will make money as others have been saying, boxing is also a big business right now.
So eventually, Casimero will have no options, unless he wanted to be strip of his belt by WBO. And this is a good fight for Casimero specially if he knocks out Butler or win in a good fashion.
Well, I have no doubt on the skills of Casimero, if Butler is really good then he should really give Casimero a problem and that is by being aggressive in the fight. We have not seen Casimero struggle against his opponent yet if his opponent is just waiting to trade punches with him, so probably this is the time.
Paul Butler is aggressive, he is not afraid to lose and this is his big break if he wins against Casimero, so it should be an interesting fight to watch.