The King made the decision directly without any consideration and hesitation.
The Eighth Son needed to come back to the capital.
The reason why he arranged this son of his to Xinzhou was because he expected that as a Lord, he was in the right position to be the chief.
However, he had not expected that this son of his would be lucky enough to defend Xinzhou!
If he continued to remain at Xinzhou, he would create endless potential trouble. All the civilians, including those in the lost towns and in the capital, were very frightened that the enemies would march to the capital. General Liu was injured and Duke North failed, so if Lord Huai won the battle, the civilians would support him like a god.
He was not going to allow this son of his to reach this kind of position, because he was part of the Jiang Family. He did not even want to keep this son of his.