Okay, this is something I've thought about for a while. I was thinking about what would I suggest to actually improve the artillery gameplay. Based on a post I made under the latest entry in Overlord's blog, here's the idea:
How about this: special cooldown mode "barrage"
vehicle can activate barrage mode once per 7 minutes. It is aimed just
as regular arty (thru the arty scope). When it is activated, the
artillery vehicle starts a barrage of shells on its target.
would be special: the shells wouldn't count as "ammo fired" (thus they'd
be "for free"). They would have double their normal splash, but cause only 1/2
to 1/4 (depending on their caliber) of their normal damage. Their aiming spread
would resemble the maximum aim circle of that respective arty - as if
it just moved (thus, the shells would cover most of the maximum zoomed-out view in artymode)
Rate of fire would be roughly one shell each 1-3 seconds, the
barrage would take 30 or so seconds. When using barrage, the artillery vehicle
can't move or stop the barrage and its camo factor is reduced to 0 (eg.
it is instantly spotted whenever someone even looks its general
direction). Furthermore, barrage shells have distinctive tracers (which
would activate when the shell is in mid flight in order not to make the countearty too easy) and sound
effects ("hweeeeeee.... boooom") so the vehicles in the target zone know they are under barrage fire and have a chance to clear out.
the aim would be to create a suppression zone, which no enemy (or friendly!) tank would
want to enter. While the damage from entering the zone would be lower,
it would be also more certain, given the bigger splash of the barrage
shells. It could create an interesting tactical element, when an
artillery stops the enemy assault dead in its tracks by covering a
chokepoint with barrage fire, or it could possibly break a stalemate (think El
Halluf or early Malinovka camping) by covering enemy positions with barrage fire, forcing them
out of their hiding spots into the open.