As long as the arty ability is limited to specific area and requires LoS, I believe there's nothing OP about it. There are other abilities that require the player on the receiving end to evacuate an area before the ability runs out/is interrupted (Airborne Company P-47 rocket strike, Stuka cannon strafe, Sector Artillery, Close the Pocket), so the argument "you can't enter the area as long as it's active so you lose map control" is not unique to this ability.
So true, i dont get it, this strike dont wipe and only pin and make longer reload ?pff so op.. Meantime 180muni stuka can wípe like mini nuke but OK and stuka loteir is 2times better than p47 airborne. Honesty ukf bombing run at liene 4vs4 its more dangerous than arty cover maybe nerf that too and maybe delete ukf as faction (y)