The whole idea of an IADS without a capable air force to complement it is delusional for two basic reasons:
First of all, even when you are using a fully mobile system like S-300, you still need to remain stationary to track targets with precision from a reference point. You cannot launch a huge missile from a truck that is bouncing up and down on the road. So, even when all components are mobile, to operate during war time, you still need to be stationary which means you can be detected and targeted by the enemy.
Secondly, even the best long-range systems like S-500 can hardly lock on targets that are more than 500kms away from them. That is still too short to stop the enemy from firing ALBMs and ALCMs over the sky of your neighboring countries. If your air force cannot create a buffer zone to prevent that from happening, your AD remains vulnerable and it's a sitting duck for your enemy. This is exactly what happened in Israeli strikes on Iran in Operation Days of Repentance and Operation Rising Lions.