Any bird hunter worth a damn outta know how to hold that 4th shell in their support hand while shooting to throw in on an empty chamber. That trick has helped me limit out a few time on wood duck.One aspect not mentioned is no marking of the bullets with a shotty. There was a shooting in Greensboro some years back and one group had pistols, the other shotties. There were no charges filed against those with the shotties as there was no way to determine who fired the buckshot.
As to the shottie having limited ammo, absolutely NOT true. If you are shooting a man's shotgun (A5), you are limited only by what you have in your left pocket. Speed feed is where its at.