Not sure I'd call "less than a single fat-SM3"
costly.
How are you getting
most of a billion dollars out of 4x CIWS? Which units specifically please.
- Phalanx runs 8-18mil, Goalkeeper on the upper end of that range. CIWS-II runs on the low end of that.
- Mk49 RAM launcher runs somewhere around 16mil for the launcher and spares, plus another 20mil to load it. RIM-116s are stupid expensive.
- The OTO 76mm Super Rapid runs about 2mil each mount.
My proposed BBG load of 6x 76mm Super Rapids, 4x RAM, 4x CIWS-II, and 4x Mk38"Mod5" (a Mod4 with added radar) is looking at ~200mil ammunition included.
One of the evolving threat profiles is attacks in enough mass that you have multiple incoming at more or less the same range. The easiest way to deal with that is simply more CIWS units and hope that there's enough distance between incoming to easily assign one as the priority target.
The fancier way is for your CIWS units to talk to each other and call their shots, but that is harder to keep each CIWS also capable of independent operations that way.
So?
The threat has changed. Over the course of WW2 we saw AA defenses go from "a few" to "cover every horizontal space available, topweight be damned" as the air threat increased.
What makes you think that packing a bunch of CIWS systems while we try to come up with cheap anti-drone options isn't going to happen?