Compare it with other 45 muni abilities - bundle nade, guards nade and now tell me again it's underperforming for its price. If you stay in barraged area you will take damage or lose squads. However I think going artillery regiment should give buffs to the 25 pounder artillery after a resource upgrade.
The bundled nade can kill several people, the arty strike usually kills no one since it takes a whole lot to call in and even then the AOE is shite and kills no one(notice that the effects are much bigger than the actual damage AOE). TBH, i think we can change this by having a liuetnant in the squad that can call in arty strikes(with a longer distance to call in than grenade throwing range, more like the US major arty range). I also want to use my non doc artillery effectively, that doesnt mean oh we gave you a shit solution but its cheap so its ok. I want to use my artillery for effect and to have an effect on the battlefield. Not just some effects that arrent worth anything.
Also why does the sextons need to be recharged to fire the supercharged rounds for 15 muni?