If it's the case that Sauros isn't taking part, then the ringleader is Philip, for the sake of entrapping James who is to be the next family head, there is the possibility he may be acting to that end.
For the Boreas to usurp the seat of the next family head, it revolves around the supportive position of the second princess, and instead they try to become the support instead or something like that.
If that's the case, then the Sylphy who has been sent, can be considered an ally.