Eh...you're fighting a real uphill battle without elite defensive players. I don't think you're wrong that the weak link may be more important than the defensive ace....but if you look at the previous champions you will see a list of teams where the majority had multiple elite defenders. I understand the Nuggets won without the most impressive defensive personnel, but like I said, uphill battle without elite defenders.
To your point, I do agree that making up for a poor defender is something that can be done in the regular season and less so in the playoffs. Like if we're starting Key+Sexton (assuming Key doesn't improve his defense), we probably can't win the whole thing even if we have 1-2 elite defenders. But you'd still love to have elite defenders in the playoffs.