I'll mention it again: where are Zarate and Canto in this discussion? Zarate lost one fight in his prime to an absolute animal (Pintor was a gip). Canto set the division record for consecutive defense against one of 2-3 best fields ever seen at Flyweight. They are both RIGHT in there.
Not sure what order it goes in (have to really think on that), but I know those two and Arizmendi belong ahead of Lopez and mix in with any of them.