One such breach does not make them accustomed to battle, nor predators. If anything, their reaction to it proves the opposite.

[Oh dear, it appears she's awakened the tactician in him. He gestures at the city spread before them.]

Not only no fighters, but no evacuation plans, places of safe retreat, secondary defenses. Nothing to suggest that they have ever entertained the thought that the barrier could fail and they might suffer a consequence borne of the outside more difficult than the continual nonsense of the weather. If these people have ever had to fear violence, they've long since deleted that memory as irrelevant.