Would their model have been sustainable? They violated the Golden Rule to the most perverse of possible extents. Would the members of such a society not have suffered due to the fact that humans do empathise? Would it have been possible for the members of that society to just ignore the slaughter of other humans, indefinitely, or would it have taken a toll that would produce rebellion from within, thus destabilising such a society that condoned the violation of the Golden Rule? Take a look at the history of slavery in this country. Any similar patterns?
You didn't answer me directly regarding Samuel's prophecy. Was he a false-prophet? Or was what was recorded falsehood?
Survival of what kind of society with what kind of values?
One that is eager to sustain life, and the will to live. One that celebrates life itself.
I think there's a good chance that if you added it all up, longevity of societies not following the golden rule win.
Would that make them of higher moral value?