So say the rules ... and the disponibility of ammunition in a rate of about 3:1 for the USA/GB, at least in the 5.2d scenario.
From historical point of view a little reference:
[...] ss-Lieutenant Damaske described the difficult predicament of the ss-Kampfgruppe Richter in the following way: "This attack also broke apart under the heaviest artillery fire we had experienced since Eterville and Hill 112 in northern France, a superiority of material we could not mach. Even during darkness and long after the attack had come to a halt, our positions were hammered without pause by artillery which had no regard for ammunition expenditures rates
From "It never snows in September" - R.J.Kershaw