The idea of a light armor shield has always confused me. If you use a shield, shouldn't you take heavy armor as you're counting on getting hit?
Of course in Skyrim the difference between armor types is minimal (and don't get me started on the armor cap), but I've always figured you either want to take no armor/light armor for mobility or heavy armor and shield for durability.

(I'm not trying to tell anyone how to play their game though, and if I did - who I am to talk, with my unorthodox methods and combinations!)