Interesting question. I am always amused at descriptions like "suitable for four people for two to three days." You don't consume the contents of a FAK in the same predictable way you can meter out cooking fuel or water or oatmeal. You can go months with no appreciable use of a FAK and then rum into an incident which will exhaust all or nearly all of its contents. I think it would be more realistic to rate a FAK in terms of incidents - "This kit can handle two or three serious incidents" or something similar. Depending upon the environment - battlefields will see more incidents per day than libraries, for instance - that kit might be good for a year or two days. So much depends upon the environment and the enterprise. What has been the history of your folks? What kind of feedback have they provided. That should be enormously important.

I would argue that a large number of medium bandaids is actually worthwhile. In my experience, you will use about fifteen to twenty band aids for every large gauze pad applied. When I had the task of stocking the FAKs in our office, I kept a box of bandaids (and a bottle of aspirin) right next to the FAK,so that people could get what they needed to treat the more typical booboo without rummaging around in the FAK and disorganizing everything.

Check with your missionary clients. I'll bet their experience and feedback will be highly worthwhile