...that I didn't bring an all-horse archer army to the fight.



If you notice the mini-map, the entire battle took place in about 2% of the map - the rest of it was blocked off. There was no way to get to the square in the center. The enemy army routed, and you'll notice went straight into the water and drowned.

This fight took place near the tiny lake between the Selecuid and Egyptian territory. Probably the fastest battle I've ever had.

Bh