sneaking past the gnoll fight to take the high-ground from the archers turned it from a hard fight to an easy one for me, but the trip of getting everyone over there without being seen and deciding when to strike was great....I like it, it's the sort of tactical realism and dramatic tension I like.
I think that the many advantages and techniques are used by the AI to represent that it's a hostile world out there and most warriors WILL be constantly considering tactical advantages.
That being said; if you haven't done any sort of actual "combat" or SCA or even martial arts, you may not understand just how great a difference seemingly subtle differences of ground/level and positioning can make.
