Couture came out of retirement when he should have just stayed retired. Couture wouldn't stand a chance against any of the top HW's now.
Brock has yet to fight any of the top HW's. Couture and Mir are notable, however not nearly enough given the current level of competition on the HW division.
The "current level of competition" has only recently started fighting in the UFC, while Lesnar was in the ******* hospital.
Why is it his fault that Dana let him walk right into the championship? You're barking up the wrong tree as far as I'm concerned.