That's where you're wrong. The reality is Mir IS that good.
Just look at his resume: broke Tim Sylvia's arm in his prime, submitted Lesnar, the first man to ever stop the legendary Nogueira, choked out Kongo, the list goes on.
He IS that good, though with that being said I'm not a big fan of his pre-fight trash talk but that's just who he is. At least it's entertaining.
The only downfall of Mir is he can't compete with the big dogs of the HW division, mainly Lesnar.. though I doubt anyone in the division can.