Artillery or Barrage?

Just been watching our attack on Armadillo. The base has a set of 4 in a square rocket launchers and another of shock launchers. Most people seem to go in with a barrage or two as their first attack on these targets. I'm led to believe that an artillery shell at the point all four launchers meet will inflict damage on all four, not shared between them, but the whole lot to each. If, for example, you have Artillery Level 13 then that will deliver 2449 damage on each of the 4 launchers meaning 9796 in total. If, by the same token, you have Barrage Level 7 (which is about where you'd have it at the same XP level), then you'd only inflict 5055 between the launchers. Doesn't that mean the Artillery is not only better value but better by any measure and the barrage doesn't become worthwhile until the Artillery costs almost twice the Gunboat Energy? Feel free to correct me if I've got this all muddled. Cheers

You are right, you havent quite accounted for the barrage hitting between targets and doing the same as artillery (because its random) but you are right. its probably just how people are managing GBE costs on weapons.