Props and elaborate drill design isn't what is getting these bands to SMC. Execution is. Something tells me that if you made every band in each classification perform the exact same drill and exact same music you would see the exact same bands making it to SMC.
The biggest difference is staffing. Yes, there are some bands with more staffing than others. Great! Let them do that. Do you really think school should be limited in the amount of instruction students are given? In some schools (like mine) core classes average 33 students. Some have more. Don't you think the school would like to lower that number to give the students a better education? If you look at successful school (STAAR results, graduation rates, etc) you will likely find they have lower student-teacher ratios. It's the same with band. These schools with higher numbers of band staff (whether full time faculty or contracted techs) are doing exactly what we should all want to do: Provide the best educational experience for their students. They have discovered the means to make this happen, so why prevent them from doing it? Now, if you are complaining about a school in your district getting more staffing than you, that is an issue with your district (I'm in that situation. There are just two of us where our sister school has 3.5 directors and is afforded a student teacher each semester). But, don't try to keep other schools around the state from giving their student the best educational support and instruction they can just because you're upset you didn't advance.