The current "Attack Area" is useful in only some very particular cases (mostly for bombing runs). Especially for artillery, it serves very little purpose (if you're in range and get either radar or LOS, they'll attack everything assuming they aren't on Hold Fire).
In oTA, I could give artillery chained orders to attack the terrain, and it would rotate through those points (very useful when blind-firing strategic artillery like the BB), which could be used to put chokepoints under continuous fire even when I couldn't keep LOS on them. It seems that a similar functionality for artillery "Attack Area" could be helpful, where it would fire randomly in the defined area until told to stop (would make it possible to actually lay Wolverine minefields without insane micro). As it stands, only the Tremor can be used for "area denial" artillery attacks.
--Dave