When IRIAF could easily see that government would fail to purchase anything in "Multi-Role Air-Superiority" from Russia or China they should have focused on reviving the F-14A fleet at all costs. In fact F-14AM program started under this pretext some 12-15 years ago to create an SU-35S out of an F-14A.
An extensive MLU+Upgradation to an Full Mission Capable F-14AM (Digital AWG-9, Azarakhsh HOBS WVR, Fakour/Maghsoud BVR, Datalink) would have costed 20 Million USD. A fleet of 42-44 such aircrafts would barely cost 1 Billion USD. In return they would make sure IAF would not be lobbing ALBMs from Iraq into Iran. Even a fully armed MIG-29M cant do that.
For Advanced Combat Training, CAS, CAP, Anti-Drone/UCAV, Anti Cruise Missile, Point Defence within IADS, yes A fleet of 120-150 Kowsars should have existed. They would have secured cities inside Iran and created crop of fully trained modern fighter Pilots.
But they are too under powered or small to do anything above Persian Gulf or Iraq. There you need powerful MRCAs like F-15E, SU-35S or 4.5 generation low RCS fighters like EF-2000 T4 atleast.