I think everybody realizes that it does not make a lot of sense to compare players or coaches from different eras because the game has changed so much. I don't think anybody would debate that point. However, I also don't think it is difficult to understand that today's game presents a much greater challenge to a coach than coaching when Lombardi did.
Where have I disputed that with the factors I have noted in a previous post about how the game has changed? Furthermore, I'm not going to assume that past coaches with the same training and experiences as Belichick, couldn't coach successfully in today's game.