The sieges will happen more often and will be more fun. Since the armies are more numerous and larger in size, ladders will be added. Eventually extra siege towers will be added too.
-Lords and other kingdom parties will siege castles more.
-Minor factions can be easy targets for kingdom expansion.
-More ladders will be added.
-Expanded street fighting for towns/cities, cities are larger so more street battles. Only of siege will be fought on the walls.
-Attackers attack from further, this allows the archers to fire more arrows.
-Defenders won't spawn on the walls, they need to fight to reclaim the walls.
-If the attackers hold the walls long enough the defenders will fight in the city streets, unless their entire army is dead.
-No more stalling at ladders, since there are more, less chance to be thrown off too.