As far as I can tell it's not the plan and what we do that's the issue, as this can change for any number of reasons as we and anyone with the slightest experience in the Corps will know. It's having the flexibility to alter staff lists to ensure the right ratios are maintained and the people actually attending are listed, without having to get into OTT admin tasks.
For whatever reason it always seems to be that the expectation is that people are going to do things that are "in excess" when changes are made, when in my experience you go for the easy life.
If as the CO putting forward for authorisation and you knowlingly sanction an activity when the person with the qualification isn't going to be there, then expect the poo to hit the fan, if it goes wrong. I've been on weekends where we have advertised something and the person qualified has had to go home/can't mke it for any number of reasons and the activity is pulled. Cadets are miffed but that's life. The plan is then altered on spec to fit what we know we can do.