The main problem with Warlords Battlecry series is that technically you did not have those 12 sides. You had a few alignments "Barbaric", and alike, between which units were divided. This basically meant that most of the sides were just clones based off main core.
The series was still fun, and brought out some great ideas.
Oh, and air units were overpowered to hell, especially once they reached full veterancy.