This mod has added many modern vanilla items—even items that should have been vanilla, but never were (such as stone stairs, walls, etc.)—and after implementing Mevans' own version of the 1.9 combat update , it seems as though he is very interested in making this mod as dynamic as possible. While shields obviously derived from the Mojang-removed capes , it seems as though they have the potential for much more than a "purely decorative " cosmetic that has little to no purpose. I suggest that shields are given 1.9 capabilities, enhancing the combat of Middle-earth—in both players and mobs.
On one hand, this added feature would seem to open the door for the planned unit capabilites—arrow cover, etc. and make combat much more interesting. However, this would bring a lot of questions to the table: Should shields be craftable? If craftable, should players have to somehow unlock the recipe in order to craft it? If craftable, what is the durability? Should shield enchantments be added? What attacks are blocked and what aren't? How dynamic should mob shields be?
Personally, if it came down to it, I would much rather want to be able to craft a faction's shield and actually use it rather than earn some useless cosmetic item.