Why didn't the Elves or Men adopt scale (or Lamellar) armor in the books
Scale is better than Mail. Dwarves and Easterlings had scale. Elves and Men had contact with both. Scale and Lamellar are superior to mail. So why not adopt it. It doesn't break Tolkien's aesthetic either, since Northern Europeans did use Lamellar and Franks did use scale.
P.S. This is to the mods. What is the context behind rule 8? Did someone actually do that before?