It's not "only" about numbers.... Initially JF was envisioned to replace all old airframes like A-6, F-7 Mirages etc. But JF is not dedicated deep strike fighter and it cannot match Mirage deep strike or strategic roles.
If you observe the block 2 and upcoming block 3 upgrades are focused on BVR, WVR, air defense and air to air battles. That shows PAF is not comfortable with JF as deep strike roles. Till any new platform (long range/medium weight) or project Azm Mirages are here to stay and fulfill the role of strategic and deep strike missions.