To attack an enemy unit simultaneously at 180 degree angles should effectively cut the unit's strength in half (like being out of supply), as the unit is now in a vice without any flanks. The exception to the rule would be the defending unit who is capable of forming a HedgeHog as a Promotion, or the unit that is naturally able to form a circular fortress, such as the Pikeman.

This tactic of surrounding the enemy was used throughout all of war, and again, its absence greatly limits the strategic war potential of the game. So, as the game stands, is it possible to mod this?

good idea for realism but i dont think this is possible.
this is because the computer only saves the unit positions - so if you reload the game they will all be facing the default direction.

Someone correct me if im wrong but i think this is the case. If so it will be very difficult to mod this in.

To attack an enemy unit simultaneously at 180 degree angles should effectively cut the unit's strength in half (like being out of supply), as the unit is now in a vice without any flanks. The exception to the rule would be the defending unit who is capable of forming a HedgeHog as a Promotion, or the unit that is naturally able to form a circular fortress, such as the Pikeman.

This tactic of surrounding the enemy was used throughout all of war, and again, its absence greatly limits the strategic war potential of the game. So, as the game stands, is it possible to mod this?

Well, it's really more of a tactical limit, but given Civ's scope, tactics is extremely hard to replicate.

I hear ya'll. But, what about this: if there is a second attack on a defending unit from a unit(s) that was never stacked with the original attacking unit(s), the defender has no neighboring tile units, and the attacking unit(s) is able to expend an additional movement point in and above what it takes to occupy the defending unit(s), then the defender is halved in strength.

Would this latter modification work within the framework of current Civ programming?