No it doesn't. College football might be a lower level but that does not mean it is easier to be a great college coach than a great pro coach. To be a great college coach, you have to be a good tactician but also a good recruiter. I don't know how much recruiting Gruden did during his college career, but his last college gig was back in 1991 as Pitt's WR coach. I know he's a great personality and that would probably serve him well on the recruiting trail, but I'd rather have a guy who has demonstrated an ability to do it in the past.
Also, the only reason you can say above average NFL coach is because he won that Super Bowl with Dungy's team. If you remove his last 2 years in Oakland and the first year in Tampa, his NFL coaching career is the definition of mediocrity. He was a completely average head coach for the rest of the 8 years he was in the league, and only went 57-55 in Tampa overall.