Planetside 2 takes place over a (in real life, rather small) continent/island. As such, there are a lot of small localized battles whose bullets, vehicles, players, etc can be calculated completely independently from each other. I guarantee you, if all 2000 players decided to duke it out over a single territory at one given time, the server will be brought down to its knees.
Since NW lacks air dropships or any mass-transit vehicles of any sort, I don't see how this could possibly work. All you'd have is a long trek between this battle and that battle, and then you might as well just have 4 different maps.