Welcome to Black Powder. I think the rules were written for more crowded 28 mm scale battlefields. I play in 15mm and have increased the artillery ranges by 25% and this seems to work. When you try historical scenarios it is obvious that the artillery ranges are too short. However I still keep the short range at the equivalent of 6 inches (6 cms in my case), this still seems to work, an artillery battery firing with 4 dice at close range is pretty dangerous., but then so is medium range with 2 dice and the -2 to save.
Regards
Garry
