The problem wasn't about just dealing with the mercenaries as no one cared about free labour and cannon fodder that didn't belong them fully.
The problem was that with the bad wood, the good one had rotted as well.
In other words, the revenge army that had come up in a hurry hadn't just dealt in killing these mercenaries and cannon fodder, but also citizens of the Empire.
The Emperor and the nobles couldn't care less about these mercenaries, but they were forced to care about their own people, and their own dignity.
What dignity would be left to a country where the enemies could enter and leave as they pleased, and kill their people whenever they deemed it necessary.
Meaning that a small matter of revenge upon some useless mercenaries would actually turn bigger and develop into a diplomacy issue.
