Well the TRUE consequence for missing is the fact they miss information and they are not getting to learn or reinforce new skills.

If a kid can't march a spot then they shouldn't be in a spot or at least have to shadow someone.

but staying in your lane is the best bet. I would just make sure that you are teaching the kids that ARE there instead of worrying about kids that aren't.

This situation sucks but you have to make the best of it.