Easy Street, please don't take offence, but I find that your ingenious arguments, for not doing this or questioning that, convince me of the need to remove such discussions from the deliberations of endless Whitehall meetings and place them in the hands of a body with the Authority to insist on the implementation of programmes, such as Military CWS, as and when deemed necessary. That would be the MAA, just as soon as they become an Authority that is.
It is all very well to say:-
if anyone thinks that it would be remotely practicable to install a CWS in Typhoon or F-35 at anything other than prohibitive cost, then please do tell how
Why not keep it simple? No bells or whistles, just an off the shelf TCAS would have prevented this accident, and would cover most other situations, with the exceptions of military formations and dynamic manoeuvres when the answer is probably to switch off all or some of the alerts.
CAT has managed the 100% fit required by the CAA, despite:-
much greater use of segregated airspace, under some kind of surveillance or control
So why can't UK Mil?
The real issue that I have with your position is that you proffer alternative scenarios of ever increasing unlikelihood in order to show that doing nothing is in comparison very reasonable and responsible. Thus was the Hercules refused ESF for decades until the inevitable (though no doubt 'highly unlikely') happened and ten people were killed.
Aircraft have been bumping into each other since the start of powered flight. We now have a very reliable system to stop it. Let's just be sensible and fit it to
all our large and/or fast military aircraft.