See, this is what leads me to believe that we're perhaps supposed to infer that the action of the play is all going on in Robespierre's head. Because the vision of the Romans given, while it doesn't seem to have a lot in common with our conception of them, does seem pretty close to general views of them in the 18th century.
But in any case, that's exactly what I mean: the Romans probably wouldn't like him much, but not for the reasons that would seem most obvious to us.
You may have a point there. I don't really know much about Japanese culture, but it would be nice if we could import the part about appreciating austerity and incorruptibility.