Haha yeah I can't do directly below or above me shots. I only learned to aim in third person, so my characteristic mess of blonde hair only gets in the way. I generally aim for enemy ranged because they are the easiest to hit at distance and are the most predictable in their behavior. Archers and xbows stand still before shooting allowing someone in a good, hidden spot (free from being shot at themselves) to patiently wait until they stop moving and snipe them. Melee I just shoot at when they are massed together and moving towards an objective. I just aim head level and cross my fingers.
EDIT: Also, drop the helmets and boots in strat battles. They only inhibit your ability to aim and are unnecessary in an organized battle. Make sure your body weight+4*(hand armor weight)<10 to not suffer accuracy penalties as well.