[Kartoffel]

152mm mail can kill anything even rough/impassable dug-in or stone building hex deployed troops, but it is more likely to harm the overeager unprotected attacker.

If you know where the enemy is use big stuff to kill even his dug in units, if not, use small stuff just to drive his troops under cover and unable to defend so when you walk up the the adjacent hex you aren't murdered by small arms.