Come on then DV, propose a better solution. Years were wasted trying to develop a gold-plated bespoke CWS for fast jets.
Just because the AAIB wrote something doesn't make it gospel, especially not when it's 20 years old. Anyone familiar with TCAS II knows that 'Descend' instructions are inhibited below 1000 feet as measured on the radar altimeter, so the lower aircraft in a proximity situation will only receive the advisory call "Traffic, traffic". This will cue the pilots' eyes immediately to the TCAS display, where they will see a plan view showing where to look out for the offending aircraft and hopefully allow them to duck under it.
Meanwhile the higher aircraft will get a "Climb, climb" resolution advisory, because these are not inhibited by low heights. So by following the instructions, the collision will be broken, even if both aircraft are hoofing around at 100 feet. TCAS II is a cooperative system, so if both aircraft are at exactly the same altitude, the system will still make a decision to tell one of the aircraft to climb.
Of course the problem of confliction with non-transponding aircraft will continue post installation of TCAS II. Have you got any bright ideas of how to deal with that, DV? Perhaps Tornado should be fitted with FLARM? There's a nice spot for a COTS unit on the glareshield, it should block the view out of the windscreen nicely.... get in touch with the PT, I'm sure they'd appreciate your guidance.