I do not know how to factor in the number of FBS schools in Ohio, but simply looking at population and the number of NCAA football schools it looks like Ohio has the advantage. 32 NCAA schools in OH ( I trusted the number 32 ) for a population of 11,750,000 is 367,187 per. ND has 4 NCAA schools with a population of 763,600 or 190,900 per.
Obviously, the number of FBS schools, aka more scholarships, and the "name brand" that goes with some of these schools is the wildcard.
Bottom line is that NDSU is doing what it has to do, with what it has, to get the job done. I am impressed that even after at least three head coaching changes they just keep winning.