"The contested city instance is capped at 48 vs. 48 players, and the winner is chosen based on the success or failure of all instances that are in play. If the invaders complete more instanced public quests, they take the city. If the defenders complete more of the instanced public quests, they hold the line."

so.. yea.. its vs players

if there are 80 players on each side, there will be two instances of 40v40
you kill each other whilst doing the quests
might wanna read before ya rant