Employment means using aircraft to fulfill a specific role. It requires practice and training to master all of the various missions that a multi-role aircraft can perform. This takes time. The pilots are not just flying the aircraft. They have to learn to perform air superiority, surface attack, escort, suppression and denial of enemy AD and a myriad of other roles in the MR squadrons of the PAF. This is what makes the employment of the aircraft a challenge for its operators. To add to this, think about all the information available to them with the integrated sensors and other PAF assets, deciding how to use the information most optimally to devise a plan of action (delivery of weapons, reconnaissance etc. while executing on the assigned mission) and you can well imagine this is a job at which you are constantly having to learn and improve.
In other larger air forces, with even aircraft that are inherently multirole, you could still have dedicated squadrons focused on one or two roles. But in the MR sqns in Pakistan, out of necessity, the pilots have to train and be proficient in all the roles envisaged for them by the PAF.
