I don't feel it's arbitrary, though, and to get a little clever about it I feel that ordered hashes are arbitrary and that's why I don't like to rely on it in _production_ code.

"Records" (aka hashes, aks dicts, aka maps, etc) are inherently unordered. Relying on insertion order or keyed values is super brittle.

So again, the fact that they are ordered is super convenient! It shines in one-off, temporary situations like debugging or writing a quick script to group something by a specific value without having to do any further sorting. But I don't believe it should ever be replied on in a production system, just for the fact that if the order ever changes, there are possibly many places that have to change.