Shared Class Limits

Hi all!

I have a client who offers classes with slightly different lengths and prices but all starting at the same time.

There is a limit of 15 clients for the total of any session but this is spread across 4 appointment types.

I've tried to use resource pooling but this is per appointment/class so doesn't seem relevant here.

Is there a better way to structure this so that the max of 15 is across all of the categories? Picture below to help:

Thanks a lot!