Not sure what makes Pedroza "better." Kid Pambele was more dominant over a similar level of opposition.
I would say Cervantes was greater, with better being tougher to call. I think that's more of an argument for Cervantes being greater rather than better. I think it could be argued that Pedroza was more dynamic and versatile.
I’ll take Pedroza for both as well. One reign of 19 consecutive title defenses vs two reigns combined for 16 total. Pedroza had some tougher fights to earn those defenses, but he generally faced tougher competition. Outside of the Lockridge and Laporte fights, I’d say he was just as dominant as Cervantes. Especially given that his reign went uninterrupted. That’s the other difference. Pedroza had two controversial wins in very competitive fights against excellent opponents. Cervantes may have only had one of those, but there’s never been much, if any, controversy around it. He clearly lost. In the ring, Cervantes was a better puncher than Pedroza, but that’s the only edge I’d give him.