Vaneyck,
If I understand your questions properly, then;
When ATC's realize that the aircraft under their control have lost (or are about to lose) separation, the natural course is to take positive action, that is the overriding impulse. To provide "if ... then" instructions is not quite positive enough, because the result is one of two (unknown) possibilities. Sitting down after the fact and considering how it might or should have been handled is not even nearly the same as being there and then, and realizing that these guys are going to get way too close for comfort.
Regarding RA's being passed to the ATC system, IMHO, the problem with that is that the update of the Radar (in conventional systems) is too slow and thus will not be as accurate as the STCA, possibly providing outdated and inaccurate advice.
When this accident happened, there was a pilot that made a statement on these forums, he said that before he did any pre-start checks or anything else, he would say to the other pilot "We agree here and now that when we get an RA, we don't think, we just do it"
Honestly, I cannot think of any better advice for flying personnel. In the same way, I hope that ATC's make the same sort of deal with themselves, regarding avoiding action scenarios.
Invictus