Problem is: where is the sense? The maps are commonly too small that the range has no effect in that game. Second is to say, a cannon ball from a 6 pounder has the same effect on a line as a 12 pounder. And I fear everyone is then using the 6 pounder, because it should have a shorter reloading time and it is faster in moving.
As an suggestion I would say: nerf the rockets! Nerf the area damage, because it could not be, that the rockets cause the same explosion like a explosive shell from a howitzer. It should make an instent kill for the direct hit on an unit and damage nearby players but dont make a significant explosion. Maybe it can set up the nearby terrain under a small fire, but that's it. And remove the damage on buildings, normally a rocket should only make a scratch on a wall!. So rocket batteries are more common in lbs, because of fun and nerfed effectivenessxD