Thanks sandhurst for such valuable information.
After reading these arguments i can understand the agony of pms/pss officers.

The logic of punjab govt to snub and discriminate provincial officers is hard to understand.perhaps it's because pms officers are are under direct control of punjab govt,while same is not the case against DMGs, Or else this undue favour to DMG may be with the aim to gain their favours when they are posted outside punjab.In any case, this attitude is not ideal: