Hi. This honestly could be documented better.
RWRs in Red Storm are defensive systems, not target acquisition systems. So, the RWR figures in to probability of being hit and surprise.
The ELINT cuts on radars, and HQ radios for that matter, are game abstractions. The radars are always "on" and there's an occasional chance you get a cut on the emitter. For HQ, it is dependent on the number of orders issued by the HQ. Nothing on map does this detection, classification, and localization. It's all highly abstracted and simplified.
So, in your example above, it's not the MI-24s that glean the firing data. It is the (abstracted) elements of the Division EW company. You could have just leg infantry on the map and get cuts.