I tried to do a search, I still couldn't find your references that predict a 99.99% probability of detection for the CIWS in any configuration
That was only my estimate* of CIWS shooting in the "fire until confirmed kill mode" against a target relatively slowing** falling from high altitude.
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*Based on the high Pk against even super sonic sea skimmers, like the French Exocet, where as I recall the Pk is in the mid to high 90s percent. Against only one "leaker", of course and also considering the "target killed" if its warhead was exploded prior to your defended point / area, even if some pieces of the target do fall on the defended area. In some cases with the supersonic targets, some of their pieces do hit the ship that killed the target via CIWS, but the damage, if any is minor.(Break a radio antenna, wind gage, signaling lantern, etc.) Lets do some numbers:
If Exocet's Pk is 0.95 (a survival Ps = 0.05) then with 8 times more time** to kill the Quasam rocket, the Ps is:
Quasam's Ps = (0.05)^8 which is very much lower than my estimated Ps = 0.000,01 (or Pk = 99.99%).
My $10 calculator will not do the eight power of 0.05 but the fourth power is 0.000,006,2 so even if their is only four times more time available my estimate of Pk =99.99% is still conservative!
**At the peak of its near parabolic, high-arc trajectory the Quasam is nearly stationary compared to an Exocet. - Lots of time to shoot at it while still high and far from the defended area.
Also note that the Pk during the second "analysis interval" (of 8 or 4 analysis intervals) is higher than in the first as the CIWS then has much better trajectory data, the target is closer and CIWS has already nearly converged the bullet stream onto the target, but in my calculation of the estimated Pk (or Ps) I have ignored these facts and assume each interval starts with poor initial mechanical aim at the target. (Not the aim being constantly improved by tracking the outgoing bullet stream as well as the target.)
If your concern is focused on detection that too is very easy compared to an Exocet. There is no background clutter, no false returns from a wave crest, no electronic counter measures - Not detecting a Quasam against the non reflective sky radar background would be like a man with 20/20 vision not being able to see his house when walking up the straight walk to it.
I also postulated that the firing rate was greatly reduced (especially if first generation CIWS now sitting in warehouses are used) as they did jam when firing at the max rate (> 3000 bullets per second). At the 100 bullets / second firing rate I suggested for CIWS against Quasams, even the first generation will never jam. (If your concern is jamming.)
I do not know if you agree now, but think my estimate of Pk = 99.99% is very well based. Do you agree?