Four barrels are most certainly better than two. The only way this could get any better is if the shooter could grow an extra pair of arms, so he could shoot another two pistols. Then you’d get eight rounds down range every trigger pull. Imagine how many targets you could hit with that. A lot, probably. I’m not too good at math, but I know that eight bullets means eight barrels, and eight is most certainly more than four. It stands to reason that more is better because there’s no way that it could be worse.
That might seem like circular reasoning, but I can sort of explain myself. If you have a gun with one barrel and you take away a barrel, you don’t have a gun anymore. The anti-gun lobbyists win, and you go home empty-handed. If you add another barrel to your gun, you can move in either direction freely. You can take one barrel away and still have a working firearm. I firmly believe that you should attach as many barrels as you can handle. At least then, if one misfires the other seven or eight will do the job.
That is one of the main reason why more is better than less. If your gun has less than two barrels the consequences could be dire. The terrorists, communists, Nazis, Illuminati, and reptilian overlords all win if your gun has less than two barrels — and you’ll look super lame.