What about the ROS and the people who work for it? How does the government recruit them?
I understand that in the ROS, RTU and places like Elections Dept, the process is rigorous from the clerks to the heads but for a long time there was no need to recruit as they are paid comfortably so that there isn't too much turnover. They are the many "dinosaurs" that private companies would retrench. That's how Robin Chan can work in the ED for 20 years. 20 years is a laughing stock in the financial sector. Even 2 years is too long in some sectors.
The ISD gets former police officers, whereas unions get the voluntary branch executives. That's how any "internal leakage" and risk is minimised.