Imo neither of the four subclasses are really "a kind of organization" - I'd probably have some mandatory fields on organization that don't belong in those. Terminus has i.e. multiple inheritance and subdocuments, so similarities could be perhaps expressed better. And wouldn't a suitable example of multiple inheritance also be cool ?
https://github.com/terminusdb/terminusdb-docs/blob/978a2a798391d91dbc9de0b81e07b60e00d959ac/guides/how-to-guides/data-modeling-in-terminusdb.md?plain=1#L32
Imo neither of the four subclasses are really "a kind of organization" - I'd probably have some mandatory fields on organization that don't belong in those. Terminus has i.e. multiple inheritance and subdocuments, so similarities could be perhaps expressed better. And wouldn't a suitable example of multiple inheritance also be cool ?