I kill ... I wound ... I will make mine arrows drunk with blood, and my sword shall devour flesh. Deuteronomy 32:39-42
The entire story takes place in just one verse.
Shamgar killed 600 Philistines with an ox goad. "And he also delivered Israel."
Shamgar ... slew of the Philistines six hundred men with an ox goad: and he also delivered Israel. Judges 3:31
The inspired storyteller obviously viewed this mass killing as a glorious, noble, and wonderful thing. To him it is every bit as cool as Ehud's message from God.
But I suspect that God not only approved of this killing, he assisted with it. How else could one man kill 600 Philistines with a pointy stick?