With the superlative the object is not compared to one other object, but to all the other objects in the referred group, meaning that the game is: one against all. Here, we find only the superiority or the subordination. Because there is no 'most equal'.
The structure of English superlative is quite easy (and to be honest it is the same in French).
Overview
Superlative of adjectives
superiority
Maria is the most beautiful woman.
subordination
He is the least suitable person for this job.
Superlative of adverbs
superiority
A greyhound runs the fastest.
subordination
A poodle runs the least fast. (not used very often)
