Our experience on the March 16 Western was different than what others described.
We had friends also on our cruise in a stateroom no where near ours. They were linked to our dining.
When we would have photos done at the backgrounds/staircase/etc the CM would ask for our KTTW card. We would do US, then US with the other family, and then the other family.
They were also at our table for dinner. CM would ask someone for a KTTW card and my DH would hand over his.
On our CD were the Photos of us and the group together, but not the ones of just their family. But the dinner photos we had them all in our CD. They were not in their CD at all.
There were a few photos of their kids and my kids together that were not on our "file" so we went and asked to have those put on our CD, and it was.
Basically, if you want your whole groups photos, just have everyone in the photo or at least one person from each, or ask to have a particular photo moved to your set.
We were not trying to "take advantage" of anything. Our friends bought a 20 image release CD, we bought the full deal plus the prints. This was $400 for a 7 night cruise. Because we rarely get professional photos taken as a family, I consider it money well spent.