One thing that annoys me about arty is that they supposedly reduced the damage to make artillery a "support" class as opposed to a damage dealer. That, at this moment, is honestly a load of crap. At tier X, arty like the CGC and T92 will regularly hit and splash fairly well armored targets for 500+ damage, and, if you are in a tank with low top armor, have a possibility to pen for more that 1k damage. In addition, because people was the big damages, they will often neglect shooting super heavies that their team desperately needs them to shoot and shoot mediums and lights instead. They really just scrap making artillery a support class in the way of stun; here is what I though of:
In order to solve these problems, artillery needs to have more of a reason to shoot at targets that have higher armor in order to help their team. So, basically, to make it more consistent, give a slight accuracy buff, make the splash slightly small, and for the damage in the splash, have it go from maybe like 450ish (for an average tier 10, so maybe like b-c:350, 261: 400, GW:450, and CGC/T92: 500) in the center to around 100ish at the edge. In addition to that, make the pen 999; essentially make it do full damage regardless of armor. This would give a very effective counter to heavily armored tanks, as well as hulled down tanks. Also get rid of stun, as this change would put artillery back into a damage dealer class, since you would be able to hit single targets for a fairly high amount and then also splash surrounding targets for a decent amount. With the accuracy, you would easily be able to hit someone your team needs dead as well. Module damage probably would need to be adjusted because full-pen HE rounds do a lot and that would be too much on every shot.
But yeah, that's it.