The conclave consists of a limited number of players. When you have an imperial senate, then the bickering grows in intensity and the situation easily escalates beyond control, especially since alliances tend to be made over issues that might, realistically, be completely irrelevant to the realms in question.
And also, these "ambassadors" tend to behave as if they were regents and make decisions on the fly that then create global interventions.
I prefer the RoE system where reliable information is not as readily available and characters act with more mistrust.