Thanks for clarifying. But I still think it is fantasy rather than fact. There is no entitlement, only convention and accepted manner of behaviour.

If for no other reason that we are talking about career soldiers, who know 'The Rules'. Three feathers for The Chief; two feathers for a Chieftain; one feather for an armiger. If they were not a Chief, Chieftain nor Armiger, I cannot see them being crass enough to wear feathers.