Fighter A. First of all his winning the championship and cleaning the division out cancles the undeserved part out. Secondly he cleaned the division out. Now fighter C did beat him but after how much time as champion? If he cleaned the division out than he had to be champion for some time. Fighter B. Unless we are talking a situition in which there is only one champion. It is going to be imposible for him to clean the division out without winning a championship. If your good your going to get noticed by a good promoter who can get that championshot for you. If your a hard worker, and it apears that fighter B is. That is even better. In otherwords the only siuition that I can think of where Fighter B gets denied a shot after cleaning the division out is if he's a Black man before WW2.
Pretty much this. Fighter A is clearly better off, because you can't clean a division out without fighting the champion. Fighter A actually does have all the scalps, fighter B doesn't. Winning the title is important, if only because you beat the badass who had it!
If fighter a is the best fighter in the world for an extended period of time and fighter b beats similar opponents but is never the best in the world. I'd definitely say fighter a.