It's true to history.

Idle men-at-arms without a nobleman to keep them in check turning brigands and ravaging the countryside were the reason for the Papal ban on crossbows - his Holiness didn't want the nobles to die out so easily at the hands of rabble, because it meant much, much more suffering for the people than winning a battle was worth . Not that anyone listened to him of course.

Likewise, mercenaries with nothing to do usually went a-pillaging just to survive, they didn't have any other means to eat but their battle wages to pay for their food, and no homes to go back to... Some wars were fought just to get mercs away from the lord's lands

And of course, your own vassals turning against you was pretty much what the feudal system was all about