They can't really do it because it is strong due to its perks, not its stats. They work together which makes it so strong. They would have to nerf firefly by reducing radius and damage and outlaw by decreasing its effect. But then they wouldn't be nerfing fatebringer. They would be nerfing every weapon with those perks. And there are a lot of those. White nail was only on BH. Firefly and outlaw, one or the other, are on almost every weapon. Or can be.