Currently, as [@Tearstone] mentioned, and I'll quote him from Skype: 

[quote]We're all good at storytelling and the like[/quote]

I'm pretty sure, for the current players involved, we can all find a happy medium here. I think, as NN stated, vague rules or theories might be best for a general overview. Then break it down into specific types (AKA individual rules/methods/player understanding) of how those elements work. This would allow easier incorporation (example: I'm going to flesh out New York City Lycans, but this might not be how all Lycans work in CAH. Merely just the breed my future PC will be.) while also allowing most of the freedom or someone to build off what I made. 

Personally, I think there should be some connections and similarities so when the magics or other elements clash, one of them doesn't feel like it's from outer space or somewhere out of this world. Unless it is of course. There's no harm in wanting some unification but let's also keep in mind what the GMS originally want the heart of this game to be: storytelling freedom.