[thatguy96]

50m x 50m = 2500 m2 right? Okay, now take, for instance that a 1970s era 203mm shell was roughly assumed to make a crater 25 ft (7.62 m) in diameter. For six shells the most serious effects (those within the area the crater) you cover just under 350 m2, or a little less than 15% of the total area of the hex, with no overlap.

Now, of course the complete effects of the shell no doubt extend beyond just the crater area (shell fragments, concussion, etc), but those effects are modeled by suppression in the instances where kills are not achieved. Those fragments and concussion aren't going to do much to an armored vehicle of any repute either. You might get a mobility kill, but even that wouldn't necessarily be guaranteed.

The role of artillery is first and foremost, at least in game, to suppress the enemy.