So the +2 modifier for enfilade is applied because of the relative depth of the target, i.e. a line enfiladed presents a many ranks deep formation. I assume that the +2 modifier also also represents the effects on morale of the target unit, i.e. enfilading fire implies that the target unit has potentially an insecure flank? Surely a similar modifier should be applied to troops who are fired on to their rear. I know it would only be a line target, but the effect on morale would be quite devastating.