Is the 5th "major league" you mention a composite of the EPL, La Liga, Serie A,
Bundesliga, Ligue Une, and the Brazilian League? Or maybe just the clubs that make it to the Champions League in any given year? If so, then I disagree with you.
I hope you weren't implying that the MLS is to soccer what the NBA is to basketball, or the NFL to football. Because it clearly is not.
Also, why limit a discussion of the world's greatest athletes to a few team sports? What about track & field, rugby, tennis, swimming, gymnastics, boxing, MMA, martial arts, volleyball, and so forth?