Can't finish off UC

[Valentine]

Can't seem to finish off the UC. The noble for Stoat runs off faster than my squad can catch because when the city is loaded in after taking down a few nobles it's attacked by skimmers, sand ninjas and a boatload of rebel swordsmen. So the noble runs out of view distance before I even reach the city then is never seen again.

I want to end the war and I've killed everything the UC has except those two farming villages (that can somehow spawn attacks) and Stoat because it's impossible even though every UC person except the noble is dead.

I'd like to move on so I can destroy Holy Nation next or something.