Bloody hell anxiao. That is a very, very good point, and interesting story.
To be fair, it has never crossed my mind to check the licence against the staff ID in the sim briefing room.
It just never occurred to me. Most of us on my fleet in hkg know each other, so it would be difficult to pull off. And also, due to inherent ingrained professionalism, it would never occur to many to even try.
But in a faceless large airline, especially with a blind eye, your story could happen! Especially when corruption, and lying about every possible thing, is a multi day occurrence, and ingrained. I could see that scenario playing out, indeed.
Ban PIA from all airspace I say, until there is an external audit.