HC, the obvious answer was found by both EHI and Sikorsky with the Merlin and the Sea Stallion: deal with dual engine failure risks by adding a third engine.
Simples.
hillberg: henra made that point ages ago, in the original thread. That is what got some of this discussion about stalled rotor blades kicked off.
Thanks for your NASA/Army test info.
Reaffirmation of "keep Nr in the green" if there needed to be any.