Well it's all in one layer really, all pointed at the portal, it just has many many weapons. There is also a squad of heavys in case anything gets through but they have never needed to be deployed..
Really? Now, thank about this. A practical god of chaos, who loves to cause chaos, hears about something like this. He wouldn't be affected by the bullets. What would happen if he were to chose to invade the portal? Not like anything could stop him.
I would invite him to go pegasus hunting. He would happily oblige, because everyone knows that pegasi are much more fun to kill than humans. Trust me, I know that firsthand. We would go off and have a great time slaughtering vicious pegasi.