Child Thread: Survey of registry namespace designs for Cargo and Crates.io

You have hit on an important point (both here and in the other thread at Child Thread: Survey of organizational ownership designs for Cargo and Crates.io - #2 by kornel): the real world is messy, and simple hierarchical designs rarely work.

Perhaps it would be better to not go down the route of hierarchical namespaces or ownership at all. Tag systems tend to be more flexible and reflect reality better. I don't know what such a design would look like in detail for this case (tag based namespacing sounds... difficult), but perhaps it is something worth thinking over.