That would simply make it more deadly to structures, infantry and tanks still wouldn't care about the shells. Just a straight, noticeable buff to AOE is the way.
I do agree with this, but I don't think its the right way to go about it, for infantry and tanks still wouldn't care, you can only make its aoe so much closer until you got almost spot on shots.
Just saying fire by volume would be a intresting way to do it. The lack of shells is contrubieing to how sucky it is.