Seeing as how I’m playing solo, maybe I need to work out a way to make it more difficult for myself when I’m playing the defense; I typically have problems when I’m solo-playing as the defender; when I’m tied into fixed positions I tend to slaughter the enemy in solo games, no matter what era/theater I’m playing. I’m really not sure how to change that, so what I typically do to make defensive games interesting is have the attackers coming from an unanticipated direction so my defenders have to maneuver in order to meet the threat.
Yes, I have encountered this a lot too when playing “solo vs. the system games”. I have been fitfully working on the problem for a new version of the Threat Generation System and an upgraded AI for Nuts!
I think perhaps the best implementation I have seen in this is in the old boardgame Ambush! when the defensive scenarios were just as tricky as the attacking ones.