For Carlos, there's only one XM referring to "CASCADE". So, it's obviously another group (i.e. ten years later).
Prisma is unknown of Kestra. but could very well be in the former group. He is listed nowhere in any Kestra prod, but they could be incomplete.
Here's my suggestion. Leave both groups and put everybody in both, save Carlos. Create a CASCADE (PC) for him.
Or add this Cascade 1733 as an acronym, but it won't look nice.