put a unit of harpies in the rear of your enemy, hit them with a chariot unit to soften them up, let them counter on their turn and kill the chariots while mixing their brigades up a bit. Then hit them with 2 knights. If cannons are present keep a hound unit between you and their barrels. when the hounds are driven back, don't move out of their way and force them to be confused and leave your front open to the enemy.
if they let you put the harpies at the rear of your enemies cannons, they will need to attempt to order them to turn around to fire on them and then attempt another order, next turn, to turn back around. if they fail to turn and fire on the harpies then kiss them goodbye next turn based on their initiative charge. if they get turned around then they might die but you have a free turn for the rest of your army with no cannons to face.
Don't be afraid to attack the flanks with your hounds. as the attacker you can put your opponent's hits anywhere you want and if they will turn the battle into your favor, why not?
the very first tactic I had with the chaos, when I was 17! was lots of heavies, lots of knights and a dragon riding hero and 2 sorcerors attempting rage of chaos all day. I can normally get that spell off once or twice a game.
finally, I liked to stack in a column, infantry brigade following 2 cavalry brigades, narrows your front just like a spear head. Cycle out your knights when down to 1 stand and let your warriors replace them next turn. 4 hits and a 4+ armor save goes along way. Chaos is only hindered by the fact they can only advance twice a turn.
