Is a Krug 'engagement' really one missile though? ~ I had the impression (not confirmed by checking the manuals I must admit) that almost all fired 2-3 missiles per target.

With 2 rounds for the engagement, the equivalent SSKP is 83% & within the range of the other missiles.

Obviously in the 'real world' nothing like this accuracy should be expected from any of these systems, especially if you have dense jamming and ARM considerations that might force dropping track, plus manoeuvring fighter targets.