ORIGINAL: Lava
ORIGINAL: SMK-at-work
As far as I have seen 2-3 point barrages cause 0-3 point damage unsighted, and up to 7 or 8 sighted. A single example of doing 21 is exceptinoal!!
Also depends heavily on the research level of artillery.
Artillery is fine. Folks don't like it, they should buy trenches or aircraft to counter its effectiveness.
Ray (alias Lava)
Trenches are fine but you can barrage far more often than you can build trenches. I've gone from trench level 3 to 0 trenches in a single turn.
Perhaps trench building could be done during HQ activation like air recon? While you could rebuild all of your lost trenches each turn you'd need to spend a lot of points to do it.