The base game has a 12km maximum range for artillery and tank units, which while sufficient for most of the weapons in the base game, doesn't allow for the extreme long range we see with weapons like coastal guns, the Leopold railgun, or other such long range artillery (152mm ML-20 has a range of 17.23 km for example).
Would it be possible to make a mod that allowed for MaxAttackRange of guns in excess of 12km. The Leopold needs a range of 64km for example to be realistic, and if you try to use it in the base 4.12.2m it's little more then a decoration.