Question about the Werewolf: The Apocalypse 20th Anniversary Edition (cWoD)

Would it be possible to add a Spirit option as they have very different dice pools and options? As well as different fera options since the form modifiers vary greatly? 

Likely. Could you be more specific? Adding Spirit otion where? And where would this "fera" thing be placed?

Spirits only have 5 stats and abilities called Charms Drattosi Drattosi are hideous creatures that live in huge radioactive pits within the Umbra. They act like gigantic mockeries of antlions, preying on whatever Umbral traveler is unfortunate enough to stumble into their mephitic traps.   Rage 7, Gnosis 8, Willpower 5, Essence 20-30 + Charms: Airt Sense, Consume Essence*, Illusory Desire* The Fera is a name for other Changing Breeds (were rats, bears, spiders etc.), When it comes to their forms, they don’t have the same 5 (some only have three) and the stat mods for these other forms can be very different from the Garou (werewolves)      As an example, the Ratkin only have three forms, Homid, Crinos, and Rodens   Form Statistics Crinos Rodens Str: +1* Str: –1 Dex: +4 Dex: +2 Sta: +2* Sta: +2 Man: –2 App: –1 Per: +1 Per: +3