I can assure you that Caergoth - Suville is totally IC as well. It's a mixture of Caergothian honor culture, dislike/hatred towards the federation and the plundering during the war, and the Duchy of Riverholm which was the start of the entire war in the first place. Steamroling Suville was an option, but then what. Caergoth would be dead in the water, with no chance against the league. There is a strong dislike still between Caergoth/Suville but both have a grudge against Strombran also.