Ok, I had the GBOD happen two times more.
It seems to occur when population is starting to run out.
At that point the AI starts spamming units like crazy, moving from first mixed units (or whatever he still has, I guess) to bazookas to troopers, which he will keep on producing non-stop in all his factories until he finally runs out of ressources - then he capitulates, if you manage to survive.
Thanks to AOE effect from bazookas and the priest's paralyze ability, which I had researched asap, I was able to hold the AI off this time, although I had to fall back to my fortified base in the second match.
It's doable, but somehow the whole loss screen after the battle seems a bit pointless if you consider that about 10-20x as many units as originally on the campaign map (even taking conversion into account) have been thrown into the battle...
I guess I would still prefer less, more expensive units, but I guess I'm pretty alone there.
Last edited by El Zoido; 18/07/13 08:24 PM.