That was the creation of Div I-AA (now FCS). Around that time scholarship limits also came more into play. And this is about where that stands...
FBS schools (formerly Div I or I-A) are to only have 85 scholarships (I believe no limit prior).
FCS schools (formerly Div I-AA) are limited to 65 scholarships (I believe no limit prior).
So definitely could see some consolidation to FBS schools after that occurred as there were more scholarships available to them then vs the FCS schools.
However, a wealthy school only had their own financial limits prior...so it could have been easier for them to consolidate talent during that time...
That said there were also not minimum requirements for the number of scholarships you had to provide to participate in CFB at that level back then. So you could literally have had neighboring teams (conference mates?) with one having 10-20 scholarship players and the other with 100+.
Now days all FBS schools can have a max of 85 but unless they are under a reduction sanction by the NCAA I believe they have to have something like 90% of them in use in order to maintain that levels status.
So many parts to consider and draw conclusions from.