I still like my Imperials as warriors. Just as ones in lighter, more exclusive armor where they are more adept to incorporate magic, charm or alchemy into the equation. Unlike Nords who I see just running straight in using the full might of their armor and weapons
For barbarian I prefer orcs who in Morrowind were medium armor. i kinda picture Orcs armies to be more like hordes of raiders swooping in to attack ( http://i1-news.softpedia-static.com/images/news2/The-Battle-That-Saved-Europe-From-Turning-Asian-2.jpg ).
The Orcish armor in Morrowind looked a lot like Samurai armor. Samurai armor in real life is made of light substances (predominantly bamboo and padding) and is relatively easy to maneuver in compared to a lot of other armors of the world.