(But maybe there is another word that could be more fitting in terms of the group) They would lead the cats in their group and do their best to understand the astrological signs that the other cats report to them. In the end he or she would have the final say on deciding what to do based on what the stars tell the cats in their group. They would also handle ceremonies like funerals, rank-ups and blessing newborn kittens based on their Zodiac sign. Delegate
(similar to an deputy/advisor/aide/ect.) While the Leader deals with making big decision, the Delegate deals with smaller issues in the group, like organizing things, dealing with problems between two cats, settling arguments and such.
And then there would be cats who read the night sky, I'm not sure what they would be called, maybe Moon-Readers
(?) They use their knowledge of the planets and stars to try to understand changes in the sky.
And then there would be other ranks, like the healers, fighters/protectors/warriors... the rest of it isn't really thought through yet, but I would love feedback.
Anyway, I might not go through with this (I'm already an admin of three groups and I don't have a premium membership, but my Pokemon one never really kicked off so I might put that on hold for a while and switch over to a cool roleplay thing.
I want to make sure that this isn't copying anything, that it's interesing, and that it doesn't sound too stupid before I think any more about it - I wouldn't be surprised if there were similar ideas out there but none of them are coming to mind.