Is Alex Ariza extremely valuable and underrated?

Ariza took Pacquiao from a scrawny Featherweight to a monster Welterweight with KO power, beating and stopping the likes Cotto, Oscar, Hatton, Margarito, etc. Ariza also turned Maidana from a gatekeeper into a hulking KO machine, Maidana destroyed Broner and gave Mayweather hell in the 1st fight with Ariza's help. Ariza also worked with Mayweather for the Pacquiao fight, and helped him beat Pacquiao. What's even more obvious: Manny was never the same after Roach began to limit Ariza's influence on Manny and eventually fired him. Maidana also didn't do as well in the 2nd Mayweather fight when Ariza was not there, having been fired by Robert Garcia. Floyd himself said that Ariza was a huge asset to Pacquiao's camp, that's why he took Ariza under his wing. None of Ariza's fighters ever get outworked. They may be outskilled, but they are always in peak physical condition. Why does this guy keep getting fired though? Clearly what he does works?