He's just a guy that Pete is comfortable working with, and who understands the drill leading up to, and on, draft day.
Any talent evaluation ability in certain areas is a bonus.
It's so much harder to run the show, the 3-ring circus, as GM, instead of just being a technical contributor, and some people just aren't built for it.
It's really no different than bringing in players... Pete (and John) know this guy's upside, they know what he's good at, and they think they know how to use him to good advantage in the Seattle system.
Think: The Brandon Browner of the draft crew. Unappreciated elsewhere, but good at beating up physical receivers and good at demolishing Wes Welkers. There's a place for a talent like that.
Having one more guy who can get the right front office people from other teams on the phone, with the draft clock ticking, and explore a couple more scenarios than would otherwise be possible, give Pete & John more options to choose from--this can only be good. Maybe a couple things go differently because of this guy, and we pick up a couple players by trades than we otherwise would have.