2 emgines shut down at quite low levels and appropriate weights to sustain a further engine failure, a la Nomrod, wonderful for ENDURANCE and loiter capabilities, but an absolute DISASTER for range capability.
Even if it were safe AND legal for civil operations, there would be absolutely nothing to gain in improved range capability, i.e. a lesser fuel burn for a specific ferry difference. One engine shut down out of 4 may make a difference.
Old Smokey