I noticed that was really weird, too. But exactly what principalagent said. I included it as an example of why the system needs some modification:
"For example, not once in the season did Leader directly score higher than Hebron, but because Leander received so many more caption awards in Class 3A (sweeping BOTH BOA competitions they attended) they got the extra 2 point lead." (https://texasmarching.home.blog/2018/11/12/my-thoughts-on-ranking-systems/#more-78)
It was only a 2 point lead, so any little changes could have flipped them. There are some flaws in the way I decided points should be awarded, but it seems like most of the list is pretty consistent with Horn Rank and actual BOA/UIL placements, and any of those little flaws are only 2-10 points apart anyway.
