as i study it more, looking at the enrollment page:
the entirety of D2 is comprised of small D1 league schools and large D3 league schools.
laguna creek is the smallest D1 school (except for Central Catholic) at 2030. there are 10 D2 schools bigger than LC. Vacaville is the first D2 enrollment school at 2020, Grant is next at 2017, but locked into D2 presumably cuz of the D3 blowback last year... they are technically a bubble school... D2/3 enrollment in a D3 league. then the rest of the division are all the smaller D1 league schools, except for Manteca.. arguably D3 enrollment, but locked into D2.
So the way I see it, the entire division was locked in due to division, except for Vacaville, Grant (bubble) and Manteca (continued success?.. not sure why they are in D2)
leagues
enrollments