@Salim Malik
Prison department has nothing to do with Police. It comes under the purview of Provincial Home Department. ASJ get training at Central Jail Staff Training Institute, Lahore. Police has no control over Jail - Judiciary checks the matters. Training of ASJ is different as compare to Police. They are given training to fulfill the requirements of the United Nations Geneva Convention known as Standard Minimum Rules for Treatment of Prisoners 1955, for concerted training of Prison / Reclamation staff of the country on modern methods. They are provided training of Prison security and to run Prison administration & management.
Driver is a different case. There is no precedent in the past that Jail Officers merged in Police deptt. Its promotion is slow but an efficient person having clear record can be elevated to the post of DIG Prison in 50 years of age. Negligence and carelessness, prisoners escape from the prison, riots in the Jail, violation of jail manuals are some reasons due to which an officer can face inquiry which may led to suspension, demotion or affect his promotion. It is a sensitive deptt. as compare to police.
P.S: You can personally meet with ASJ or Police officials to confirm.