FF's always had a few pieces of stupidly broken gear/magic. It's part of the franchise. As for Odin dropping "worse" stuff than Fafnir,
you tell me how any of these are worse. (Particularly when they can stack with D ring)
and just for shits and giggles
If those two items aren't the best helm and body a PLD can wear then IDK what is (especially with D ring, Hauteclaire, Aegis and Askar Feet)