While both muShkavAn kastUrI and duShTa-bejha are of high intelligence, my feeling based on the available evidence is that muShkavAn has a distinctly higher IQ. By bejha’s own admission there were folks with atmospheric IQ in his college class. But they have not become anything like him. It does suggest that vaNiktva is a distinct ability.
An atmospheric IQ fellow might get bored doing the kinds of things bejha delighted in. muShkavAn takes up various ventures to satisfy some of that quest for novelty.