Well, FinFan, in my post, just before this one, had you bothered to read it, you would have seen the facts. I'll expound on it here. Mike Mularkey did indeed coach the offensive line, his first coaching job, in 1993 in college. He did it for 1 season. Then he went to the pros. In 1994 he spent one year as a quality control assistant for Tampa Bay. I understand that position is mainly involved in breaking down film to help the coaching staff analyze how its own players are executing. Then he moved to tight ends coach, also for Tampa, in 1995. Following that, he spent five seasons as tight ends coach for the Steelers. He was named offensive coordinator in 2001, holding that position three years before coming to Buffalo after the 2003 season. This is from the biographical sketch at:
http://www.buffalobills.com/team/index.cfm?show_right_rail=no&cont_id=224466
Tight end is actually a pretty good background for a head coach. He is exposed both to blocking like a lineman and the intricasies of the passing game. Many tight ends are very bright guys, and more than one have been coaches in the NFL. It's true that Wannstedt has been in coaching for a much longer time than Mularkey. Experience has some value, now doubt, but everyone has to start somewhere. Wannstedt got a head start, of course, because he did not play professional football. Mularkey had a nine year career. At least the Buffalo players think there is a benefit to the fact that he actually played professionally.
Also, if you'd read my post, you'd know that Aaron Schobel had 11.5 sacks in 2003, enough to tie him for ninth in the league. There are 64 starting defensive ends in the league. I'd say ninth place is pretty good. Jason Taylor didn't have 11.5 sacks in his third season. He had 2.5. Michael Strahan didn't have 11.5 sacks in his third season. He had 7.5. Mike Rucker had 9. Yes, there have been a few DEs that had success early, including Ogunleye, who was also in his third season last year, but statistics say you're wrong about Schobel. He is a lot better than mediocre. By the way for comparison purposes, Jay Fiedler is not ninth in anything and he only has to compete against 31 other starting QBs. His best showing is 15th in fewest interceptions thrown. He ranks 25th in total passing yards and touchdown passes, and 23rd in passer rating. As you say, that is true mediocrity.