Keep in mind the largest Class A high school in Nebraska, from an Enrollment standpoint, would be roughly the 20th largest 5A school in Texas.
Many 6A high schools in Texas have more than 4000 students. Allen, TX having one HS for a town of 100,000 people is absurd. But it explains why football is so great. The population to pull from is immense.
As for 4A, there are close to 25 schools in that classification that would fit into class A enrollment in Nebraska. And from a numbers standpoint, that would make the competition a lot tougher.