I rather regard these Night Pirates nothing but brainless punks. But since they are a very large group, we should not underestimate their power.
As the saying goes, 'Capture the leader first if you want to disintegrate a group', if you can take out the pirate captain with your partners, it will create a great disturbance among these pirates. Of course, I wouldn't mind if you can kill some more minions along the way. The pirate captain should be in the deepest of the Night Pirate camp.
If we can create some kind of disturbance, it should keep them busy for a while and unable to attack Schilling Village. Any spare time is useful as what we need the most now is time.
I will leave this job to you and support the operation behind you. Once you have done the job, report to Stiffany. I will keep watching our enemy in the dark.