JFC, people, you hire a head coach to assemble a coaching staff that fits his vision of the football team.
You hire a General Manager to hire regional and national scouts, a director of college scouting and a director of pro personnel to aquire the best players possible to fit the head coach's scheme.
It's not the other way around. Andy Reid is the most proof that coaches with personnel decision don't do either job well. Jimmy Johnson in Miami is another example.
The Team President runs the marketing and business side of the operations.
As for Pittsburgh, Dick Haley ran the personnel in the 70's and 80's, Tom Donohoe and Tom Modrak in the 90's and Kevin Colbert since the early part of 2000.