E.g. https://en.wikipedia.org/wiki/Historical_rankings_of_prime_ministers_of_the_United_Kingdom and https://en.wikipedia.org/wiki/Historical_rankings_of_presidents_of_the_United_States have rankings that give the contenders various kinds of ordinal rankings. Are there any rigorous theoretical frameworks that might underlie current and potential future attempts at relative and or absolute rankings?
To cite a contemporaneous example, there has been much public commentary on the performance of UK leaders, vis-à-vis the issue of Brexit.
What objective criteria do historians et al use, in attempting to construct such a ranking between the performance of David Cameron, Boris Johnson and Theresa May?