You want a guarantee of success, or else, you'll accept just mediocre to sometimes good.
There are many possibilities. I don't pretend to know who that person is that would bring guarantied success. But that doesn't mean I don't think there is someone that could lead ND to a championship. The great coaches at ND have not come from obvious situations. One thing they all have in common though, is none of them needed 11 years to get ND over the hump.
Jack Swarbrick should have a list of candidates that he keeps if he needs them. That's what a competent AD would do, and I think Swarbrick is at least that. Hiring another head coach from anywhere would not "guarantee" anything. But we know the one we have has not gotten ND where most want her to be, even if he's better than the one's immediately before him. If whomever is hired does not do the job after 5 years, hire another. You keep hiring until you find the one who does do it. The ND I loved did not accept the low bar that has been set.
I trust that you want ND to win as I do. Maybe, you feel that it can't be done. Like I wrote, that's another argument and debatable.