Why would you put an air-defense weapon on the perimeter? Being on the perimeter exposes it to direct fire from outside the wire.
Wouldn't a ZSU-23 have the range to defend well from well within the compound? Or does it have an alternate use, can it be depressed enough to take out ground targets?
I'm not questioning the ID of the weapon - just what were they thinking with the placement.
I think they are likely there predominantly to engage ground targets. The perimeter gives them an open field of fire.
Its not an issue of range, but seeing your target. The perimeter is generally cleared of obstructions and an attacking force would have to cover a lot of open ground. Although an old school weapon, the ZSU-23 would be fearsome weapon to have to contend with if you had no armor.
I’m thinking JDAMs would be the best preventive medicine, but that would give away the element of surprise.