where is 4 milion player ?

[Whocareswhatmynameis]

I'd imagine a huge chunk of those extra players are Chinese and Korean as they just launched in those regions recently.

In 3.1 Bismarck and Ravana will be added to duty finder, probably with echo. It won't be easy beating it in duty finder though as everyone just treats it as a learning group. At the very least you'll be able to practice it more, and then set up a Party Finder group to beat it.

Also If your really serious about endgame, I'd get on a more popular server like Gilgamesh or Behemoth, you'll have a much bigger Party Finder pool.