GF:
It's the way you wrote it. I didn't find your mixing systems level risk assessment with actual flying in response to a power loss (twin or single) to be a lucid way to frame your position.
I have flown both singe and dual engined helicopters. The advantage to having two engines is that sometimes, when you have a loss of power, you have a second engine to help you do something other than fly that auto down to the bottom. Fly it, which means control Nr first, and then see what your engines are giving you. If it's your good day, you can use the good engine to fly you home. If it's your bad day, you are flying as you should be and have a chance at a decent auto all the way down. (and on your really good day, you have some altitude and time for a possible restart, depending on why the engine stopped. The whole time you are figuring this out, you are controlling Nr, flying the bird. Helo pilots can multi task ... it's in the nature of helicopter flying).
It is what tends to happen before Nr is controlled that I am
highlighting.
Really? Are you telling me that you don't teach that control Nr comes first? (Say it ain't so).
Even with a partial power loss, or a compressor stall in one engine, or a roll back in one but not both engines, the First step is
Control Nr
and the implied associated first step is fly the aircraft.
Time delay in acting is another topic.
Nothing further. Out.