Well, if you want to keep RPF and FPF together, I hope the categories for RPF are chosen because they work for RPF, not just to keep it all the same.

I don't have a real favourite between the two approaches I laid out, and if someone has another idea, I'd love to hear it. Categories do two things to my mind, they lead readers to pages, but they also lead editors in making pages.

I think fandoms as individual categories will help editors to make more pages in FPF fandoms, since the category is clear, but if you have to determine a new category whenever you make a new RPF page, will that hinder page creation?