Well Roger's is a bum. Overeem was just the first guy he fought talented enough to show that. Overeem lost mostly to elite LHWs in their primes while Fedor was fighting Zulu and Kohsaka. Prime Shogun would wreck Fedor in the first also he has never faced a single fighter as good as shogun in his career.
Shogun who lost to Forrest Griffin ? Shogun who lost to Mark Coleman ? and Babalu who Fedor both beat ?