I am not sure I understand the point of your post and your definition of a David or a Goliath in terms of high school football today. It is true that St. Francis of Watsonville with 213 students is by far the smallest CCS school fielding an 11 man team - the next smallest schools are around 500 kids co-ed. But if you look at the section rankings they have little to do with the size of a schools student body.
Steve Sell and The CCS did St. Francis a huge favor by putting them in a bracket based on a teams computer ranking rather than on the size of their student body. If the CCS just did brackets by school size they would have been the #8 seed in a DV bracket with Palma, Sacred Heart Prep, Scotts Valley, Soquel, Half Moon Bay, Santa Cruz and Menlo and played Palma in the first round. If you took out the 3 small A league teams (Palma, HMB, and SHP) and only have the smallest B and C league teams in a bracket this year you would still have a bracket of Menlo, Santa Cruz, Soquel, Scotts Valley, Pioneer, Hillsdale and San Mateo. St. Francis would have been a #8 seed playing Menlo in the first round. I doubt that St. Francis would have even been competitive in a first round game against either Menlo (584 students) or Palma (694 students)in those brackets.
The CCS has it right by not counting school size. As a result, St. Francis was able to beat Cupertino (student body of 2173) and Los Altos (student body of 2209) and is playing a 3rd place B league team in the finals in Aragon (who lost to Menlo 48-7) with a student body of 1762. These are not David vs Goliath match-ups - these are teams competing in relatively fair brackets based on their season performance.
If St. Francis of Watsonville wants a fair match-up based on a school size maybe they should consider playing St. Francis Academy of Baltimore who only has 208 students (but is ranked #5 in the country by Max Preps and came to Northern California this year and beat De La Salle 42-28). It is time to stop counting or considering the size of the student body as a barometer for defining the strength of a football program. St. Francis of Watsonville is fortunate that the CCS has done so. Good luck in the finals.