Mayweather's workrate at 130 is pretty high and before his hand problems and his going up in weight his power was more respectable. Chavez's own output would drop with the feints and threat of counter punches.
Maybe the blueprint was watching the problems that JLC gave to PBF first time out... And JCC is many nothces above Castillo in every facet of the game. At this weight, Chavez was incredibly heavy-handed and fought with a ton of tenacity. Maybe PBF, could move his feet, counter and keep a safe distance. But, Castillo gave him many problems and I have to think that Chavez would do much better... It`s a damn good and close fight...
But Chavez has much heavier,slashing hands than Castillo regardless of weight. And it`s a relevant comparison... Ecxept that skillwise Chavez is MILES ahead of Castillo...
Chavez would open Floyd up with his feints and combination punching. Floyd's output would drop, his defence would look less than airtight, and he'd take a pasting. As I say, different levels.
The blueprint is the second fight. Even though Mayweather won the fight, wasn't injured and was fully prepared for Castillo, he still didn't look very convincing dealing with Castillo's methodical pressure.
Your leaving out the fact that Mayweather's great against the ropes. If your going to pull a Castillio comparesan. Sure Chavez may rough Mayweather up, but like against Castillio. Mayweather will land the better and cleaner punches.