The "Constitutional Debate" in Herodotus (Book III.80-82)

Background:
After seven men overthrow two brothers who attempted to usurp the throne, they gather in council to decide what to do for the future.

Note that in the following paraphrase of the debate, much of the terminology used is not actually present in the Greek.

Note that the gods have no role in the debate.

Note also that it is highly theoretical and abstract: it makes no reference to the particulars of the situation. There are those who think that in inserting this debate here, Herodotus is engaging in an anachronistic fiction. Others insist, as Herodotus himself does, that the debate must have occurred.

Otanes' Speech: Megabyzus' Speech: Darius' Speech: "Theory of Unchecked Sovereignty"
Is " who will rule?" the fundamental question? or is it "How should we construct the system so that good rulers do well and are rewarded, while bad rulers are reigned in and disciplined?"

Issues raised:
What is inevitable?
Stability as a value.