What I was trying to do was challenge the idea that
all band activities are or should be automatically part of the band class and grade, especially in the situation the op described. In a small school there really aren't enough students to go around for all the sports and other extracurricular activities.
In a small school a band director is lucky to have a viable band at any time. I know that in much of the country high schools have become these huge 3000+ student monstrosities where you really might be able to pretty much pigeon hole students into categories like jocks, band geeks, drama, or whatever, but in smaller schools it's pretty common for students to participate in multiple extracurricular activities.
When I was in high school (early sixties) I was was probably the biggest band geek we had. Concert band, marching band, jazz band, pep band, pit band for twice a year talent shows, dance band. Only concert band and marching band were part of the grade. I also ran cross country track in the fall and played baseball in the springs. Neither of which conflicted with band for the most part. And drove a school bus. (Remember when school bus drivers were students?)
Driving the bus was a handy thing as our band room wasn't even at the high school. It was at the junior high / elementary school and we high school students had to bus over for band class. A bus driver in the band meant no one else had to take care of that particular chore.
But, during football season a number of the band students weren't available due to participating in that sport. Same for basketball. Our band was never bigger than about 30 people and more like 20 during football and basketball seasons. You can guess what a half time show must have been like with only 20 people in the band
Point is, small schools just aren't like big schools and thinking that it's actually a reasonable thing to require all the possible band activities as part of the class can defeat the music program. I truly believe that in a small school a band director is much better off concentrating on bringing along the (likely) half dozen (if he's lucky) musically talented kids he has. If he's a really great and inspiring teacher then he'll build a band program that students actually want to be part of without having to resort to grades to get them to participate.
A carrot is usually more effective than a stick.