So my world was turned upside down a bit yesterday when I learned that you are supposed to use Precision Hookset to catch Ala Mhigan Ribbons. I have done a lot of fishing in this game and have always use Precision for fish with light pulls, and Powerful for fish with medium and heavy pulls.

Is it just based on their average weight and completely unrelated to the type of pull they cause on the line? Ribbons are a small fish, and I also noticed I caught plenty of Gyr Abanian Trout which are also a small fish (but again have a medium pull).

Basically can someone explain it like I'm a 5 year old? Despite feeling like my previous rule of thumb (ignoring their weight number and basing my hookset on the pull) has always worked great, this recent revelation has me wondering if I fundamentally misunderstand the system.

To add to confusion, I was just out catching my Castaway Chocobo Chick. That has a tiny weight like the Ribbon, but you use Powerful to catch it?