i think I see your point.I think Blaine was pretty dangerous enough. And don't forget the pred gets into battles he fights against multiple enemies. And with killing with wristblades would easily give his position also. He just cannot be at too much places at one time. So I think pc is okay.
But I agree with you. If preds would use mostly their great physichal abilities and melee would be good. Or just stick to their great hunting tactics. I think pred 1 was really imressive on that.