This talk of Coughlin going to the HOF seems nuts to me. He was a good coach, but better coaches like Mike Holmgren aren't there so I don't see Coughlin making it.
As a Packers fan I agree with you that Holmgren should be in. But he could be a little rough around the edges at times so I think that may be whats "holding" him back. He should get in soon though this year would have been nice since its the Packers 100th year.
RE Coughlin.... he has a very good case. For starters, Tom Flores, George Seifert, Jimmy Johnson and Mike Shanahan are the only other 2x SB champion coaches not in. Everyone ahead of Coughlin on the wins list is either in, lacks hardware/playoff success (Fisher, Knox, Reeves, Schottenheimer) or is still active (Reid, Belichick). He brought two franchises success, in Jacksonville's case the AFC title game in only their second year as a team, then won two titles with the Giants which also came against the best team of his time/era. He's 7th in playoff wins as well.
Plus the Giants factor helps, its similar to playing/coaching for an NHL O6 team.