In an Insider piece, ESPN analyst Herm Edwards looked at the weaknesses of six top teams .The good news for the San Francisco 49ers is that Edwards thinks they are a top team. The bad news is Edwards thinks that they have a major weakness. His choice is not surprising -- it's the lack of receiving weapons.Here is some of what Edwards had to write in the piece:Yes, Michael Crabtree and Mario Manningham eventually will come back, but they aren't going to solve all of the problems.