Sure, that sounds reasonable. If the lord of that ruined city married the daughter of the ruler of either Arman or Arhus. Then if all the princes died and the kingdom had to be inherited down one of the female lines, I could see that independent lord pushing a claim for his children against some inbred that he wouldn't consider a threat.

Of course, in the resulting war he would end up having his city razed and probably end up joining the Dominion of Terus in an attempt to keep what little land was left of his realm. At that point reinforcements from the Dominion would probably be able to repel the invaders.