What ordonnance for what situation?

[Slaists]

that is not true. i always play on highest unit sizes, and i still have trouble hitting anything but the ground behind them.

Well, then try playing on a smaller unit size. I bet, it won't be ground 'behind them', but ground 'off the field' ;)

By the way, how do you do the targeting bit? You realize, you should never try to target units with artillery? Rather target the ground where you anticipate the unit to be. Or, the ground right in front of a unit if it's still.