Artillery is needed to prevent campy gameplay, but with its current design it's either hardly doing anything or insta wiping squads (or at least that's what relic made it to be in the past). So here is my proposal: give all artillery a rather big AoE with reduced damage, so it can't wipe squads (at least not 2 or 3 rockets) but give it supression / crew shock. This way arty wouldn't be a "oh you're capping one of my sectors - WIPE THAT SQUAD!"-tool but be helpful at supporting an assault at defensive positions, as you could damage and suppress the defending troops so your assaulting troops have an easier time.
If this change leads to arty not beeing able to handle bunkers / units in buildings etc., maybe give it an ability to shoot higher damage shells with massively reduced AoE so it can't be used to easily wipe squads and maybe require some munitions to use it.
So, what do you think?

Edit: Like Burts mentioned, the game would probably benefit if other long range weapons like mortars, ISU, etc. (all those AoR weapons capable of wiping squads) and mines would be changed accordingly.