Nonito has tiny hands there's a pic of him somewhere with Barrera and Juanma Lopez and they had huge hands compared to his. Nonito always had serious power.
It's already been discussed. The mass of a fist is irrelevant on a punch that have the body weight behind it. You could never break hands just by throwing them as projectiles. You smash them because you have the weight of your entire arm behind it, ( 15-20 times more mass than the fist?), plus part of the weight of the body behind it (dozens and dozens of times the mass of the fist). Result= fist size is meaningless in punching power. It does, however, affect it's ability to not break, wich is a crucial aspect for a boxer.
Joint integrity is the biggest determinant of punching power. Upon impact it is at the points of joints (wrist, elbow, shoulder) where the power is either transferred to your opponent or “leaked”. It is at the joints where this leak occurs. Robust, steady joints is where the mythical power is.
Well take a look at Trumps hands. Most powerful man in the world and he has hands like a 12 yr old transgender boy.