I would bet a top Texas high school team would give a Division 3 football team all they could handle. I wouldn't be surpised at all if a high school team from Allen, Katy, or Plano, TX would beat a team from WCSU or ECSU by 21. Playing a Division 2 school would be a challenge. I don't think a top high school team could beat a competent Division 2 school.
The coaching at the top of Texas high school football is extremely good. And some schools attract families from all over the country to move there just for football. One top Dallas area school needed a QB and suddenly two nationally ranked QB's moved there from Minnesota and Houston.