There is not a lot of overlap between the categories of “top undergraduate business schools” and “D3 football”.
D3 football programs are most commonly found at smaller schools, especially liberal arts colleges (LACs). However, LACs don’t usually have a separate business school. In fact, LACs don’t usually offer degrees in “business” at all, although they typically do offer degrees in “economics”. Economics is a traditional liberal arts discipline, while “business” is not.
Undergraduate business schools are commonly found at larger universities. But larger universities typically play D1 football. Only the nerdier universities play D3 football.
There are hundreds of D3 football schools, so it’s much faster to do this in reverse – start with the USN&WR ranking of Top 20 undergraduate B-schools, and see if any of them play D3 football. Here are the D3 schools on the USN&WR list:
- MIT
- New York University (D3, but no football team)
- Carnegie Mellon
- Washington University in St. Louis
- Emory University
http://colleges.usnews.rankingsandreviews.com/best-colleges/rankings/business-overall?_mode=table
So there are only four D3 football schools on the USN&WR list of Top 20 undergraduate B-schools. These four schools can be reasonably regarded as “nerdier universities” (as per above). You will need very high grades and test scores to be a competitive candidate at any of them.