It seems the underpinning problem was that each individual was working to an incorrect mental model, and was disregarding any information that didn't fit. Why and how would your suggested system change that?
It is reported that TCAS greatly increases SA and reduces workoad.
Typhoon has numerous other sensors which can build SA, in addition to the measures that have been mentioned above: planning, deconfliction, CADS, an ATC service, not to forget the rev backup of looking out the window and doing a proper scan!
In AVM Atha's Tornado safety statement of Oct 2013 he points out;
"Current technical mitigations are based on systems used primarily for alternative purposes other than for bespoke aircraft-aircraft spatial positioning and avoidance"
This statement carries the following footnote,
"It is worth noting that equipment mitigations are rarely mandatory items for a flight to proceed. As such, these can at best be considered as aids to deconfliction"
In other words unless you have a bespoke system you could end up with parts of your CWS unserviceable. Of course ECAS will not be a bespoke system, even when they get it working. A bespoke CWS would be a 'No Go' item.
DV