Always a challenge for sure to find a good coach. ND has struggled since Holtz and UM struggled post Carr. I do believe that timing mattered. Recruiting really started to take off on a national level in the mid-late 90's and early 2000's and that is when UM, PSU, and ND went through their struggles. If there was on thing Cooper could do it was recruit. OSU hired Tressel, who by and large put a fence around Ohio and sprinkled in elite guys from elsewhere and then of course Meyer went full blown national landscape. I think OSU has always had the jump on the rest of the B10 in terms of resources and knowing how to use them (best facilities, lots of money, national branding, using alumni networks, etc.).
Regardless, you are right, there is no guarantee but I believe there would be a long list of highly qualified coaches who want to be the HC at OSU, especially considering the cupboard is not bare, yet.
Ryan Day is the first OSU HC since who (?) with no previous HC experience (Woody, Bruce, Cooper, Tressel, Meyer all had HC experience prior). Day is a great offensive mind, but not a great HC.