I certainly think Napier can get a P5 job. However, I believe it will be difficult to get a top level P5 job first thing. Not always, but the top level schools tend to go with coordinators from other top level schools. People like Mahlzahn (sp?) and Freeze who have gone from G5 HC to P5 HC have usually had some association with that school before rejoining. Napier's only associations have been with Clemson, Alabama (neither of which will be open soon) and Arizona.
This is not to say, he couldn't land a job like Auburn, but the cards would have to fall just right to do so. I believe it much more likely that he will have to take a lower level P5 position first, do an outstanding job at that school, and then be in a position to move up.