Attack on Sight – Bandits
This will work better if you give your men the "attack enemies" job.
This will cause your faction to attack members of most bandit factions on sight. They won’t wait for your command, and won’t wait until they’re under attack.
No AI changes are involved, I simply made your faction HATE these factions so the vanilla AI will attack them. The current version doesn’t include mod-added factions.
I don’t currently have walls up to verify this, but I believe this would also prompt turret users to fire on sight.