I really like the battle system in Empires.
However, many of us have noted that cavalry plays a very limited role, especially when both sides have enough troops to fill their frontage with infantry.
Cavalry often played a decisive role in these battles. I think a similar effect could be create din the game by reserving the rightmost ans leftmost spaces in the frontage for cavalry only. Or even the rightmost two spaces and the left most two spaces. This would apply only in open terrain, such as plains and desert, as cavalry was not decisive or even very useful in rough terrain. It would not apply to siege assaults, of course.
This would allow cavalry in these spaces to get flank attacks on non cavalry units, unless opposed by cavalry.
Sometimes, in FOG 2, a well positioned cavalry unit can make multiple attacks in one turn while rolling up an enemy line,especially when they are engaged in combat with units to their front. A way to recreate this possibility in Empires would be as follows....
If a cavalry unit in one of the cavalry only spaces destroys the enemy cavalry to its front, it may make a flank attack on the enemy cavalry unit in the other cavalry only space. If there is no such unit, it may launch a flank attack on the closest enemy unit to it. If IF it destroys that unit, it can attack the next, and so on until it fails to destroy a unit. This would prevent players from just using light cavalry to occupy the cavalry only spaces, and make it wise to have strong cavalry units in them.
I do not know if this is possible, and it would change the balance of the game. But in the great victories of Hannibal, and Alexander the Great, and others, cavalry was often decisive, something that is not currently recreated in Empires.