Dear Patrick,
Another option is to take some of your artillery ammo and blow them up(by setting up one of your guns point blank to the rear and shooting them) this eliminates the Guns permanently and you do not have to occupy it to keep the points. It does take time, you have to secure the area and bring up your guns, turn the captured guns and extra artillery ammo; however, use of artillery ammo in this way may cost you later if you are not prudent.
Note a captured 2 gun battery at the end of the battle reverts back to your opponent as two Guns and at the origial quality for the next encounter. If you destroy them he only get one gun back.
a Quirk of the game engine.
Lt Gen Joseph C. Mishurda

Lt General Joseph C. Mishurda,
"Killer Angels"
VI Corps, AoS, USA