Lol, now I know what happens when a routing SC that won't die and has pathetic damage output is surrounded by 500 undead, and the only way out is through a tartarian. Answer: the tartarian slowly gets worn down to a nub, routs, and is followed by the entire Ermorian army.
Unfortunately, the person who routs first still loses.
And I'm saddened to report that "Piggles' Revenge" froze to death while happening to be in the path of 50 retreating wights. He was destroyed by the first Ermorian unit that reached him, a skeleton. This is a poor omen indeed.