Curufin is one of the guardsmen now. He isn't actually a law-abiding type, but he joined because his son is is in the Guard. So, now he's obligated to stand with his coworkers, especially if their own leaders have apparently turned against them.

He won't initially realize that some of them might not exactly be reliable, either! But once he does, he'll try to band with any of them who are alive and not their Evil Twins.