All artillery that is available in game is just mortars and the Self-Propelled Guns. A good addition would be more static artillery, like from ArmA 2 OA. And while I'm at Static, some anti-tank cannons would be a cool addition; missiles are boring. Automatic guidance simply requires a soldier to point and lock on; pointing, aiming, and shooting is a fun thing to do. It's like having a tank, but without the tank, mobility, crew, or turret.

Request:
Static artillery batteries (like the M103 or D-30)
Static anti-tank cannons
Static anti-air cannons (like the ZSU from ArmA 2 OA)