That's kind of my whole point. We don't know how they are separated/represented under the Accords.
Based on Ortega's actions regarding the dual, his actions could be interpreted as believing they were all one vampire nation.
We know that all of the vampire courts are different types of vampires with different hierarchies, different territories and different --
sometimes mutually exclusive -- goals.
We know that the White Court and the Black Court hate each other.
We know that when the Red Court went to war, the White Court did not and in fact acted as a neutral party trying to get a ceasefire.
We know that the Jade Court is very invested in not being involved, while the other vampire courts are very invested in being involved.
We know enough to indicate that the Red, White and Black Courts are not all one nation under the Accords. Why on Earth would the Jade Court -- which has shown no affiliation to any of the Courts and is, again, almost totally isolationist -- let the Red Court make decisions for it?
It's basic common sense that you do not have someone with different interests and goals from you talking in your place. It would be very stupid of the Jade Court to just not care who's speaking for them in a binding treaty.