I really appreciate what you're doing here. As a Artillery veteran, now working as a defense professional, I am very excited by what you've accomplished. While I don't know much about game design, I do have a variety of references I thought you might find useful.

The best game implementation of Artillery systems and doctrine I have seen is Battlefront[www.fireandfury.com]. What I think you may find useful is their detailed descriptions of Artillery operations as a game system, as well as frankly impressive research of the artillery doctrine of major combatants in the Second World War.

The standard reference for professionals in the field is Field Artillery and Firepower[www.amazon.com], though some prefer On Artillery or [www.amazon.com] On Gunnery [www.amazon.com]. One text used to instruct Canadian Gunners at the Royal Regiment of Canadian Artillery School at CFB Gagetown is Fire-Power: The British Army Weapons & Theories of War 1904–1945[www.amazon.com] which explains the foundations of Commonwealth doctrine and artillery-centric warfare through the present day.

I know it is outside the scope of ArmA mods, but as you have added rolling barrages and other fireplans, I would also recommend World War I Battlefield Artillery Tactics [ospreypublishing.com] a nice 64 page overview of the evolution of Artillery during the First World War with excellent illustrations and explanations of time on target missions and box and rolling barrages.