Now as for Riombara... I think we all agree that a clash between Thalmarkin and Riombara is inevitable. Only I was hoping Riombara's war against Enweil would've strengthened them and saw friendly colonies spring up so that this whole thing could turn into a huge continental war of North vs South and make it a war worth fighting. If it doesn't get to that point... then we just have to find other ways to create challenging conflicts. And being a bunch of ginormous douche bags taking another realm's stuff just because we can seemed like a fun way to get there.
That's not going to happen seeing how the war has caused the noble count in Riombara to decrease to the point where they have 5-10 more regions than nobles. Even if it did I think both sides are rich enough to line their entire coastline with militia so it would take forever for a battle to take place.