The trouble is that the AI is basically crap. Perhaps I am being dim, but there appears to be no downside to the pretty basic "pound one enemy location until he goes down, then move to the next" tactic. Why doesn't the AI use this? Because it's crap.
May be some problems with the random seeding.
i.e. in my first game I had at least eight series of 6-7 misses on 30% likelihood, which should be very unlikely: 0.3^6 = 0.07%, so I should have seen this roughly once every 1,400 battles - and I didn't fight 10k battles.