I have taken the time to do a 2v1 custom battle. I engaged 2 roman units against spartan general in an encirclement and watched the results unfold. The outcome was quite simple: The unit facing the formation performed 10 kills, the unit behind performed 20 kills. Spartans, at the time of breaking the unit facing it from the front, inflicted upon it 47 casualties, and 1 casualty to the unit behind it. I ended the battle at the time of the frontal attack unit routing as it served the research purpose. At this point it has been able to outperform 1v1 unit in a 4.7:1 K/D ratio. Continuing the battle would result in the routing of the second unit in the same manner. Assuming the K/D ratio, the spartans would finish with a total of 40 men lost (out of 105) and 2 roman front line infantry units routed. (spears were not used during any point of battle). During the battle AI did not switch the frontal position of its unit at any point. During engagements they usually have multiple units and thus are able to hedgehog a small square so that their formations face enemy infantry from all sides (kind of a noob square) etc. I find this behavior to be broken as it allows exploitation of this formation.
Personally I don't really care I'll smash the AI anyway, but from a roleplaying perspective/immersion, this is just plain wrong.
(yeah I know the screenshot is cut in half but I wasn't really paying attention to what I pasted in MS paint).
Any further objections to the issue should be re-read before posting.