Comparing him with Couture is outrageous. However, Mir is actually not that outrageous. Who has Mir beaten other than Tim Sylvia, 1-0 Lesnar and the worst Noguiera we've ever seen? Mir at the end of the day is an average fighter and always has been.
So who has he beaten outside of 3 of the last 4 UFC champions? Stopping all of them? Is that what your asking? Even if you pretend that isn't 1000x more impressive than Rogers, I was really more basing it on the fact that Mir has been fighting at a high level since the pre Zuffa UFC, and outside of his two fights after his comeback from having every bone in his leg turned into dust, he has looked damn good doing it. To compare that to a guy who's biggest accomplishments are knocking out the two worst chins in the heavyweight division and calling out Kimbo is incredibly stupid.