It may just be me, but unit rosters need to be reworked in my opinion so we the AI always has some form Spear/Sword/Shooter/Cavalry combination. Units such as the "Woodsmen", "Archer", "Spearman", and "Medium Cavalry" (all just examples) could be considered the basic level of unit production for European states, modified by that factions exclusive units. As to the Arabic and African nations, I am not sure what one would consider "basic" among them - Desert Archers, Bedouin Camelry, Arab Infantry, and Spearmen?