I have talked to an FPSC official dealing withh this case. He confirmed that the seats are same as advertised i.e. 08. The reason of requiring documents again and again is
Candidates do not posses relevant/post qualification/exact organisation experience.
Also, it is usual that people apply and appear just to take chance, he added.
Now, you all should be clear about confusions and wait for the final list. Remember me in your prayers!