ANFI the rules, generally, mandate a “spare” engine to be carried when the helicopter is over terrain or taking off and landing in areas where loss of your engine (failure) would be catastrophic for you or persons and property below you. END OF ARGUMENT.
Loss of the single engine, in a SEH, over or into a congested area, wooded confined area, oil rig, water, scree scattered mountain slope, people, power line etc generally ends very badly. END OF ARGUMENT.
A catastrophic TR or MRGB failure in either a SEH or MEH will end the same way for both machines.
Now I am wrestling with the a pig and more than a little worried that I might be the pig!