Billy T I do have one question?
What about the excess projectiles that do not hit the incoming target?
What happens to those? the projectiles on most CWIS are either Explosive or Hard---Tungsten, Depleted Uranium, or a mix, and what happens when they come down,
You could end up killing more of the citizens( and they take a very dim view of killing them to defend them) you want to protect, than would be killed by the incoming rocket and Mortars.
Once you let a projectile out of the barrel it is on a ballistic trip that you can no longer control.
The best solution is still destroying the launch capability of the aggressor, that is why the defense for the fleet begins over the Horizon.
The reason that a CWIS can defend a ship miles away is that the sea surface is flat, and the ship RCS can be easily discriminated on the surface, but even then one of the problems from WWII in anti aircraft fire was against low flying aircraft, the Trip A between ship, hitting and killing crews on friendly ships.
If I am correct that was one of the reasons for the AEGIS radar, it is a battle control system that keeps track of the friendly ship and has programs to lock out targeting of friendly ship.
The other thing is that as the range increases, the kill probability decreases, and in most battle formations a CWIS that is defending a sister ship in the formation would be doing so at the extreme end of the systems range.
The CWIS is and was designed as a close in defensive system, and it is the last stop on a layered defensive system that starts over the Horizon.
It is as we say, The Oh Shit, Leaker Coming IN!!!!!!!!!!!!Defense.
CWIS is and was designed for defence against single incoming targets, not 10 to 40, incoming targets, and those are numbers of rockets launced in a single attack I have read from news reports, they migt have a good effect against 1 to 4 incoming targets, but against 10+???
Bullets that go up must come down, and in your case on friendly territory. .
The HE shells yes can be timed fused, but the DPU and Tungsten, are dumb.
The reason for the DPU in the mix, is if you don't get a hard kill of the warhead that it nocks the incoming missile off course into the sea.
Now if you don't get a hard kill of the war head it still come down some were else and is still a danger to your population.