Hi Ed. Thanks for that explanation.
The wall could be anywhere, not necessarily at the edge of the scene.
I have seen the enemy retreat to the edge of the map in many cases. So maybe this occurs because the AI thinks that it can find the only usable wall there (in those cases the wall was placed at the edge of the map as a part of one of those fortifications which are usually placed there).
During retreat they will take pot shots if you pursue them, but only if they have high chance of scoring a hit.
That is true, but it doesn't happen frequently and only few soldiers will stop to return fire. Most of them keep sprinting to reach the wall. I think most of them don't try to shoot because my soldiers are quite far away and out of range for light weapons - but they are within range of my sniper weapons.
I think in fact, having different groups of enemy following different strategies make it more unpredictable for the player.
Yes, I think that will make it more entertaining. So one group could prepare a real ambush instead of only returning fire half-heartedly :-) Maybe you also could tweak the AI to not always look for the big wall structures that can be found at the edge of the map in most occasions. Instead it could look for other (smaller) walls etc. which can be found in other parts of the map.