It never seemed able to coordinate attacks specifically aimed at turning the flanks of its enemy, and would usually just stumble forward to oblivion. Very dodgy tactics, if you ask me. Anyway, I would recommend taking the attacking units to get your best challenge. The Fog of War option was simply an option to allow you to see some or all of the unit statistics for the enemy. While I must admit Fog of War in a game where ranges are less than 1000 meters seems a little overdone, it is still an option.
Visibility is another option that represents the ability of a unit to notice an approaching enemy.
This plays a very strong role in bad weather scenarios where detection ranges could be measured in feet, not yards. Again, the value of this with the short range of combat for the scenarios listed is not really proven, but is available. Weather is a very key element for any tactical level wargame, because it affects so many other things. In Medieval , the type of weather exerts influence over the maximum sighting range, the movement of your troops, the percentage chance that missiles will hit their target, and the ability to charge at and overrun an opponent. Needless to say there is a big difference between shooting an arrow in clear weather, as opposed to in a driving snowstorm.