An asset can look correct in its source application and still fail after import into React Three Fiber. Treat hierarchy policy as a translation problem between tools, with node ownership and parenting and naming checked on both sides.
For React Three Fiber, separate source, working, and delivery files. Use stable names for nodes and dependencies, remove unused references, and include a manifest that explains what the downstream user actually needs.
Define which nodes carry geometry, animation, collision, metadata, and reusable grouping before cleaning the scene tree. Apply this hierarchy policy guidance to the actual React Three Fiber delivery path.