Some ranks in FernClan are:
Instead of a leader, in FernClan there is a king and a queen. When deputies are appointed, there are two, a she-cat and a tom. If the king and the queen die, they are forced to become mates even I they had a mate before. Any offspring of the king and queen cant become deputy (because that's kinda gross).
Tree-jumpers: Most cats become these, they learn to climb trees, hunt, fight etc.
Herb-specialists: Basically the medicine cats
Low-ranks: There are a handful of cats who become these, unless they have serious potential, nothing increases or decreases a cats chances of becoming one of these. They are basically servants for the other ranks, and are treated badly. Sometimes they get to be mentors, but their apprentices usually boss them around. If food is running even a little bit low, no cat will hesitate to kill off some of the low-ranks. They aren't allowed to have mates or kits.
(I just wanted to make this like a kingdom sorta)