Non-barding variants of things like Lamellar/Steel, O-yoroi, and Kikko are metal. Barding versions are all, for some reason, nonmetal type and Kikko is also cloth eqmod (not sure if others are incorrectly cloth as well).
I'm sure the standard armor types are correct and the barding ones were just a copy/paste error or something.
UE Page 11 has the armor list but then the descriptions are across various pages. I would just default to trusting the human armor types and duplicate those really...
Confirm your list of error's - I cleaned up the file, but everything seems in order.
Not sure I understand, are you saying you don't see the issue? Example:
Barding (Lamellar Cuirass) PROFICIENCY:ARMOR|Barding (Light) TYPE:Armor.Light.Standard.Nonmetal.Barding.Mount
Lamellar Cuirass PROFICIENCY:ARMOR|Lamellar Cuirass TYPE:Armor.Light.Suit.Standard
Note the extra Nonmetal flag.
Barding (Armored Coat) - also EQMOD cloth in barding, leather in armor.
Barding (Kikko) - likewise, also eqmod differs, cloth vs steel
Incorrectly Nonmetal but eqmod seems ok:
Barding (Agile Breastplate)
Barding (Mountain Pattern)
Barding (Kusari Gusoku)
Barding (Agile Half-Plate)