Fran Brown is a decent choice. The others are, to me, bad fits.
Ash has shown he can produce a decent defense when given a roster of HS AAs. We don't need a coach like that, who, when provided with decent talent, was a collosal failure. He was an awful hire for Rutgers and would be a awful fit here as well.
We need someone who can do more with less, who has shown he can develop players and out scheme good coaches.
Jim Leavitt is 62 and could not get a job as a paid assistant this season. He would require a huge salary and I don't see him busting his butt to turn around Syracuse. Even if he came, he would leave at the first chance he got to coach at a school that is a better fit for him.
Charlie Strong, if he doesn't get another HC job, is going to be among the highest paid assistant coaches in the country. We aren't going to compete with Alabama, Georgia and Oklahoma for coaches. It just isn't going to happen.
Plus none of these guys has strong connections to the Northeast, where I think are having major problems recruiting.
Fran Brown is the only guy on your list that kind of makes sense. He comes from NJ, an area we need to have coaches with connections. He has had to identify raw talent and develop it coaching at Temple. He has never been a defensive coordinator though (he is listed as a co-defensive coordinator but Jeff Knowles is the DC at Temple).
I think we need a youngish, hungry , personable guy with ties to our traditional recruiting areas, experience coaching up talent and experience as a DC. This is not the time to go cheap and hire someone who has never coordinated a defense before (or spend a ton on someone with bad qualifications who is poorly suited to the task at hand).