To note, I did mention counter-UAS systems, to clarify, I meant gun based systems (including but not limited to SPAAG) networked with radar.
I've already considered gun-based systems previously.
The effective range is like 2km. You're going to need really large numbers to cover the possible targets.
In any case, remember that you would plan on Shaheeds arriving at the same time as an airstrike with accompanying SEAD aircraft. And the gun systems have to reveal themselves when engaging targets.
But let's take a hypothetical engagement.
A SPAAG costs like $15 Mn.
Let's say it is really, really successful and shoots down 40 Shaheed before running out of ammo.
But one of the following Shaheed has an SDB-2 type guidance system which can autonomously identify targets, and destroys the SPAAG. The cost of Shaheed munitions is still 9x less than the cost of the SPAAG.
Again, in an arms race, large numbers of Shaheed beats SPAAG gun systems.
And when you have large salvoes of Shaheed, it is worth mixing in a few different guidance systems for different types of targets.