Why include the ghost and artifact? That makes no sense. Ghosts can drop from all packages and artifacts can't drop at all. The way I see it is if your 380 for example, the rewards on average drop two higher/at 382. If you have 2 weapons at 382 and 1 at 380 you only have a 33% chance to get a higher drop. If you have 2 pieces of Armor that is 382 and the others are 380 then you have a 50% chance of improvement.