Aristocracy and Power

Since 'aristocracy' means literally 'rule of the best', the proposition 'aristocracy is the best type of government' is tautological.  Accordingly, Nietzsche's treatment of "aristocracy", in Beyond Good and Evil #258, is less informative than he seems to take it to be.  Nor does equating 'best' with 'most powerful' help him, since that merely converts the initial proposition into another tautology, i. e. 'the rule of the most powerful is the most powerful type of government'.  The latter emptiness is a symptom of another, in addition to the one previously discussed, methodological lapse in his presentation of the doctrine of the Will to Power--the lack of any precise definition of 'Power', accompanied by an exhaustive evaluation of alternative concepts of it.  Now, one plausible tack such a construction could take is a continuation of what is briefly proposed in #257--the synonymy of 'Power' and 'comprehensive', leading to the formulation that the 'best' ruler of a collective is the one with the most comprehensive vision of it.  On that basis, traditional alternatives, notably Theocracy, Plutocracy, Military Rule, can be evaluated, so that e. g. if suppression or neglect of part of the collective is involved, the structure is less than 'most comprehensive', and, hence, is an inferior type of government.