It would be for Plate armour smiths better to add new thing to reach like Damascus steel which you would be required to combine all the metals that you can mine from regular veins (Wogic = iron+tin+copper+zinc+gold+silver = Damascus steel). And remove Iron plate armours that just makes all the plate armour smiths that are out there think they had golden shower on them. But if not removing could be changed to bigger difference in DEF between steel and iron plate armours.