Easy to do when you have a band staff 3-4 times bigger than most 6a and free private lessons from that staff. As is the case with most of the valley bands.
The judges actually do score the bands. Look at the results and look at the number with the rank. They then rank them based off the score. So they do exactly what you said.
Brazoswood had their SMC appearance vacated in 2016 because they had an ineligible student helping with the band on the field. Might be what you heard.