Supression to arty is retarded, basicly if you ever get cought in a barrage you have to auto-retreat. Micro to dodge shells would be pointless thus less skill.
AoE of supression won't be big and I think it should affect only direct-hitted squads and small-small area around. For to avoid that situations with "1 shot - all retreat".
B-4 arty will have bigger AoE suppresion btw...
And what do we think about "direct hits in vechiles causing small damages (stun, turret lock, vision closed...) or with very low chanses - engine damage"? Would make artillery more effective as support guns.