There are many ways to counter SP Artillery:
The best one is probably Railroadgun, specially for the range, but they're a bit slow & costly to produce.
However, normal Artillery, SP Artillery, Rocket Artilleries & sometimes even SP Rocket Artillery are good enough to counter them.
Apart from these, there is Air force, that can do the most damage in the least possible time, but, if the enemy stack has anti air units good enough to counter your Air Force, then it'll be a serious problem.
And, the last option you have is spamming lots of fast Armored Cars or Light Tanks or Mech infantry or Motorized infantry units at forced march to deal the highest possible damage.
The best one is probably Railroadgun, specially for the range, but they're a bit slow & costly to produce.
However, normal Artillery, SP Artillery, Rocket Artilleries & sometimes even SP Rocket Artillery are good enough to counter them.
Apart from these, there is Air force, that can do the most damage in the least possible time, but, if the enemy stack has anti air units good enough to counter your Air Force, then it'll be a serious problem.
And, the last option you have is spamming lots of fast Armored Cars or Light Tanks or Mech infantry or Motorized infantry units at forced march to deal the highest possible damage.
