This tension is between the taxonomic and cultural. This is a bit of a problem of structuralism. In museum exhibit design, it's doesn't make sense to group artifacts by language groups, because same language speaking cultures can have vastly different culture

Instead, culture zones are much more useful, because geographic areas have day to day interactions and end up having more coherent similarities between their cultures. So I think a comparison to TTRPGs would make sense. Mechanical similarities doesn't necessarily mean similar cultures of play