First off, you can't use luck as a bonus. Yes it's part of his story, but it's just a plot shield. Second, we have no idea how powerful the guardians shields are. What I said at the bottom of my first post was a joke aimed at the and TLW. We do know that Chiefs armor is the same as the other Spartan twos, and that means pretty flawed, the shields are weak, don't always work, and the armor is especially vulnerable to plasma burns. In comparision, guardian shields don't seem to appear in lore, but if their armor can deflect most of their weapons, that means that it's pretty strong. It's pretty self evident that guardian guns are much more powerful than Halo guns. I really don't think there is much that the Spartans can do except get up close. If they even get there, supers would finish them off.