I think something ought to be done about friendly fire from cannons. Today i set up for a battle like so:

Line Inf - Cannons - Line Inf - Cannons - Line Inf

The enemy was facing exactly opposite, quite a fair distance away from me. I forgot to unlimber my cannons before i ended the deployment phase, so as the battle started i immediately clicked unlimber, which they did, but i also turned off fire at will, because i had specific orders for them.

At this point the cannon unit i have highlighted in bold turned its gun to the right, facing the entire length of my line, the barrel aimed perfectly. Then, it fired a ball. Took out the ENTIRE back row of the line infantry unit, 40 men out of 120 dead, took out a fraction of the other cannon unit, and half of the back row of the line infantry on the end. The worst thing is, there was nothing whatsoever in the direction the gun fired except empty land. I unlimbered, the enemy was dead ahead, the cannon turned to the right and shot through its own line in a perfect straight line.

If CA can't stop the AI from deploying its soldiers in front of its own cannons and dropping like flies with each shot, or they can't make artillery behave itself and follow basic orders, then i say turn friendly fire off altogether for arty.