My interpretation is these are not soldiers but civilian ponies who were forced to defend themselves. Real soldiers are trained to fight. They would not cry when they have to use their weapons. This is still a nice concept and the art is amazing. It's interesting how the one firing the gun has a flower for a cutie mark. Was that suppose to be a dichotomy?
eyupp. personally though, I'm a big fan of the M2 Browning .50 cal. Not a gatling gun, but it's seen service in the Pacific, Europe, Korea, Vietnam, Pretty much everywhere ^^ now there's something to be said for that!
The original gatling gun held 40 rounds max. But because it was gravity fed, it could be loaded at any time during operation, much like a belt fed machine gun of today. Just clip on another belt before the other one is used up. All though this one seems to have a closed box magazine, which never existed with the gatling gun.