~~They have sometimes acted as mediators during conflicts and may have slightly influenced border resolutions in their favor as they establish peace agreements.~~

Edit: I'm better satisfied with this answer - Diarcesia has always been a religious pluralistic nation. That isn't to say that religious conflicts didn't happen. Some diereses are more religiously homogenous than others. Adherents of minority religions, depending on the historical period, become sources of tension or bridges that dissipate them. Border-wise, their influence is greater in smaller diereses (sanctuaries during conflict) or in rearranging established regional/international borders especially in the 19th century.