Quote Originally Posted by Arcturion
I prefer to use small but elite army stacks to fight my enemies. This means they usually outnumber me, and come after me as a result.

I also prefer this general formation:

Missile Cavalry_____________Missile Cavalry
Cavalry_____________________Cavalry

_______________Archers
____________Heavy Infantry
Light Infantry______________Light Infantry
_______________Javelins
_______________General

Set up the cavalry as far ahead as possible on each wing. The missile cavalry's job is to charge ahead and try to catch the enemy in a crossfire like so:

Missile Cavalry--->___Enemy__<---Missile Cavalry

The heavy cavalry's job is to stay close to my missile cavalry and keep the enemy horses away.

When the enemy comes into range, my archers will fire on them before moving behind my heavy infantry. If my heavy infantry consist of pikes, I usually put them in a spear/pike wall and hold formation so the enemy runs into my spears. If my heavy infantry consist of swordsmen, I will countercharge them against the enemy. Either way it will look like this:

___________________Enemy
_______________Heavy Infantry
Light Infantry_______Javelins_____Light Infantry
__________________General
__________________Archers

I like to put Javelins behind the Heavy Infantry as they are usually armor piercing and stand a chance of killing the General. I use my General as a reserve to charge if any part of my Heavy Infantry line looks like breaking.

After my Heavy Infantry has engaged the enemy, I will move the Light Infantry up on both sides to flank the enemy. I will also try to charge my remaining horses into the enemy's back.

___________________Cavalry
______Light Infantry__Enemy__Light Infantry
_______________Heavy Infantry
__________________Javelins
__________________General
__________________Archers

Of course, you need to vary your tactics depending on your enemy's troops as well, but this should be a standard formation.
I tried to do what you said with armies of equal sizes, and I had an average victory =) the enemy actually killed 20 more men than I did (around 680 as opposed to around 660) but they routed far more.