The following is a part of the section 15.70 of A Comprehensive Grammar of the English Language (Longman).
Rachel is no more courageous than Saul(is).
The sentence implies that both Rachel and Saul are not courageous( 'Rachel is not courageous, any more than Saul is courageous').
They are no more scholars than my baby (is). ['They are no more scholarly...']
The rhetorical effect of the construction is not so much to make a comparison as to intensify the negation.
Since it is absurd to say "my baby is scholarly", I can notice that this sentence has a rhetorical meaning. But, in the first example there is no suggestion that Saul is not courageous. Does the no more ... than construction automatically suggest that the proposition of subordinate clause is false? Or, does it depend on the context (so, it only has the literal meaning if it is taken out of the context suggesting that the proposition of subordinate clause is false)?