The reality is as follows:

New Offensive Coordinator (promotion for Head Coaching job)
New Offensive line coach (was the only one fired, was also the run game coordinator)
New Wide receivesrs coach (promotion for OC job)
New Defensive line coach (promotion for job in NFL)
New Co-offensive coordiator Position in staff (not a new coach, just shifting some responsibilities)
New LineBackers Position coach (not a new coach, just shifting some responsibilities)
New assignment to Run Game coordinators responsibilities (shifted to the RB coach)

Last year PSU was #15 nationally in scoring offense and #8 nationally in scoring defense. And they hired the OC from Minnesota who was #21 in scoring offense last year. Their DC is still there. The projection is that they will have 8 returning starters on offense and 5 returning starters on defense. So really the defensive experience would be the biggest question mark. But the coaching resumes they have across the board are very impressive and are not a weak spot for them.