They are not unknowledgeable because of their opinion. Bas Rutten and Guy Mezger are certainly 2 of the most knowledgeable people in MMA in the world.
Fighter rankings are changed after every fight even. So i agree about Fedor but it doesn't mean he cannot ever be number 1 on the rankings, It's rankings and they don't mean to much. Couture has beaten Sylvia and Gonzaga pretty recently in very convincing fashion so i would agree with them there. Fedor may be the best fighter in the world at the moment but he is not ahead of Couture on the rankings.
It is similar to Serra and the Welterweight division, Serra is a good fighter but is he the best? and he has the belt. Fedor may be the best but Couture has the number 1 position at the moment.