Warhammer Fantasy FAQ II
Q. Can models get a better save than 0+ (i.e. a negative armour save)?
A. Yes, this is possible in theory, but certainly not easy to achieve!
Q. Can you allocate attacks to specific enemy Rank and File models in order to force which enemy Rank and File models count as casualties (and are thus unable to fight back)?
A. Yes, however we have to warn you that zooming in to a fight to this level of detail is likely to make resolving your fights a very slow process indeed!