In OPEN FIELDS, what's the difference between the other coming to you or you coming to the other?!! I think the combat system in Civ III isn't accurate on this...
If a unit that isn't better in open fields at defending its position than attacking, it shouldn't get a difference between attack and defense in such fields. Look at spearmen, archer, knight, etc. They were as good at attack or defense in open field. Someone attacks? They see them from far away and go to them. It was ranged combat or charge-to-kill-the-guy, so no difference.
Here's my verdict: the difference between attack and defense should exist only for units that are able to profit more than others from fortifications, cities, or of a surprise or well prepared attack (such as legions or impis). Otherwise, viva Civ II system (ameliorated please). If a unit isn't advantaged in open field, shouldn't get any advantage.
If a unit that isn't better in open fields at defending its position than attacking, it shouldn't get a difference between attack and defense in such fields. Look at spearmen, archer, knight, etc. They were as good at attack or defense in open field. Someone attacks? They see them from far away and go to them. It was ranged combat or charge-to-kill-the-guy, so no difference.
Here's my verdict: the difference between attack and defense should exist only for units that are able to profit more than others from fortifications, cities, or of a surprise or well prepared attack (such as legions or impis). Otherwise, viva Civ II system (ameliorated please). If a unit isn't advantaged in open field, shouldn't get any advantage.