The Extraordinaires should definitely be the Smartest.
We have Isaac Newton and Ludvig Van Beethoven, two people who are believed to have some of the highest IQs ever.
Magneto is a very bright villain, while Mr.Fantastic is a very gifted scientist as well. The Marlboro Man convinced millions and millions of people to smoke cancer sticks. Yoda is an extremely smart Jedi, if not the smartest. Peter the Great caught up a very underdeveloped Russia with the rest of Europe.
My team is built for smarts. Even Woody Harrelson's girlfriend in 'White Men Can't Jump' was on Jeapordy!