I think different vehicles should get access to different arty.
Scouts would naturally have the greatest range of artillery as they are the best equipped to identify targets and provide correction of fire.
I also think artillery should be a modification similar to selecting different cannons on a plane.
Artillery should be selectable for callibre and shell type based on BR, vehicle class and technology level and based on tech tree.
Different artillery systems should have distinct characteristics, i.e: accuracy, rate of fire, shell/missile/rocket types available, number of guns in a battery. Barrage type, walking, static, concentrated, spread.
(Example being, guns with higher rates of fire will fire more shots per barage.)
(Shells types, smoke, airburst, mines, cluster, HE, Willy Pete, I don’t know many rocket artillery types but maybe fuel air bombs?)
Nation and Rank Specific, US and Germany at 3.7 wouldn’t have access to 25 pounder barrages for example. But Brittain might have access to 155mm.
Given that I’ve suggested this level of detail, maybe we let players have artilley controlled separately like a UAV drone, and the player needs to aim and fire their own shots based on grid/map reference. This introduces the option for skilled based arty play, a teams battery could be an offsite location similar disance to a helicopter airfield that spawns randomly at one of a set few locations. This allows arty to be strafed by planes or cannons to fire counter battery etc. I’m well aware that this is getting dangerously close to the shitty Wot artillery.