Your main idea makes complete sense. I was viewing it from a game dev sense of being able to drag the folder into the engine and boom now you have em all and they're sorted. But in my brain I just love having the sets separated, no issue with how you're doing it. But if you do choose to keep em in the same folder maybe just add like fish_ or beast_ to the name to organize them that way. I do myself enjoy having em all in a single folder and seeking through a hundred folders can become a task on its own XD
However this goes I'm game either way (n_n)