Iron banner supposedly has level advantages activated, right? So in theory it should work similar to PvE, because they are active there as well. A level 1 couldn't even damage an enemy that is level 20 because their weapons are too weak and the enemies armor is too strong. Iron banner? Guns do the exact same damage to everyone no matter who you're fighting. Try it for yourself. Pick a gun, and use it for a few games. Pay attention to the damage that you do on each person depending on their level. You will do the exact same no matter who you're fighting. THAT proves that level advantages are not working.