Last year, the NCAA committee serpentined teams into the two races based on a)national rankings, b) regional rankings - while trying to get a split of teams in the same region into opposite races.
At least on criteria a) we can guess the likely race assignments for the top teams
Grouped together would be
Stanford
Oregon
Georgetown
NC St
Iona
Michigan
William & Mary
Arizona State
Notre Dame
New Mexico
Utah State
The next race would be
Colorado
NAU
Weber St
BYU
Indiana
Central Michigan
Dartmouth
Butler
Duke
Montana State
Then non-ranked teams will be put in, and I wouldn't want to guess how they would do that. This assumes that I have done it the way the NCAA committee will do it - but it's how they did it last year, and has Buster Hymen ever been wrong?
Interesting is that the second group is heavy on the mountain and great lakes biggies. While the first group has the three top dogs from the west. Just the way the national poll fell out.