There is a big difference between being a scholar of something like Bayesian probability or game theory and desiring to apply rationality in your life. Thus, there is no contradiction between believing that Aumann could run rings around anybody here when it comes to the relevant mathematics and that he might be far less rational in his everyday life than the average LW reader.

It's wrong in general to assume that somebody who researches a topic is influenced in their day-to-day activities by their research. They usually just find it an intellectually stimulating topic that they enjoy working in, and the only effect it has on their non-academic life is that they sometimes think about it outside of the university.

Expecting Aumann to be extremely rational is like expecting philosophers of ethics to be extremely ethical.