I think it said SKyforge armor was the best armor, not Daedric, and I think it said Nightingale Armor is the best Light armor, not Dragonscale. Also what is Guild Master's body? It said that body has more AR than nightingale body for Light armor. It even has 1 more defense than heavy armor Daedric
Daedric is the best armor set in the game, period. The Guild Masters gear is better in certain areas, but it's not a complete 4piece set, so you lose a ton of Perks. Nightingale is the best Light Armor, yes, but I don't know if it's already enchanted. If it is, then you can't do the build mentioned in this thread, because you need all enchanting slots available.