Imagine you play as a team of True Sons against a team of Outcasts. Players get to use each faction's archetype. You could think of it like Team Fortress 2 with The Division factions, similar to the Echo near The World's End control point.
Edit: People are telling me to check out XDefiant. I did, that's why I made the post. What I was trying to convey is player classes are much closer to the classes within the different factions. Your team of 5 or 6 can choose one to be a Tank, one to be a Thrower, one to be a Rusher (maybe better without the Outcast Rusher imo), one to be Assault, etc.
XDefiant looks like it's taking liberties with the source factions. I'm just as skeptical as the rest o