I place my troops just like that.75% of my cavalry is on the left side with 25% of my missile units,this way the enemy believes that i am going for a flank attack and he will place the majority of his cavalry on that side.He will usually place his missile troops behind his infantry and maybe some cavalry on the right side.

All the army will move forward engaging the enemy.I have superiority on the right side so i must kill or rout all the enemy's cavalry and then move my remaining troops behind the enemy infantry and attack his missile units keeping them occupied,a few units should attack the enemy's infantry on the left flank because your troops need a bit of support.In the left side my troops have to resist the enemy attack just a few minutes till i finish the enemy's infantry.

In meanwhile ,this is how it should look in the middle of the battle..

The two "arms" of your army should squeeze the enemy like that....

When you get here there is no escape for the enemy......muhahahaaaa