DB, hear what you are saying. The specific example I quoted involved a transporter climbing out over high terrain and a fighter descending on top of. The RA gave a climb for the fighter and a descent for the transporter. That is exactly the sort of time you want both aircraft TCAS equipped.
The other example I quoted, my own experience, involved a head on potential collision at Herc cruise levels. You see you are relying on the other aircraft being able to see you. In my case, neither Herc had TCAS and to this day I don't know how we missed.
One thing is for sure, if this equipment has not been requested, there is no way on earth you will get it on board.