This is a small group in comparison to the majority who attends the schools. For people like that, an exception can be made instead of trying to make it the norm.
Something like that gives us, as instructors, an opportunity to show students that we are willing to work with them so that they can train at your school. This is where the instructor becomes less like business and more like a caring person which in turn can strengthen the relationship.
If you normally have 5 classes, then make 3 of the classes regular classes and 2 of the classes special class. For example, my school does 5 classes a week. 3 regular classes, 1 sparring class, and 1 day for extra training if the student missed a lot of classes. The extra training day also can be used like a personal training opportunity if 1 or 2 people show up. This is a bonus for the student because learning is usually accelerated for the student.
Here's how it looks when you market it.
School A
Trains 5 days a week
Students have 5 regular classes
School B
Trains 5 days a week.
Students have 3 regular classes, 1 sparring class and 1 day extra for students who need additional training or for students who may have missed some of the regular classes during the week.
Both schools train the same amount of days but School B looks like it has more options and it appears to have a special day of training set aside for students who may need additional training.