In general* if an xONEn has any flights via Africa, South America or SWP, it MUST at least be an xONE4.

* There's may be strategic routings available to avoid this, but they come and go and generally the rules get changed to ensure a minimum xONE4. e.g. For a while, AA flew ORD-DEL (NA-Asia) and the rules were changed specifically.