Is it though? We don't have clearly defined metropolitan/provincial/country areas. For a small nation such as NZ, maybe met/provincial would be the more logical categories, but regardless, we don't have them.
And many of the biggest trainers are based at the likes of Matamata, which would be deemed a country town and is certainly not a large city. I think that categorisation of that type is unworkable in our country.
And that was the very idea that - from my recollection - started the downgrading and subsequent underfunding of smaller clubs, to the detriment of all. John Wheeler started the Queensland winter campaign idea, and floated the idea [ to the then RIB incumbent Garry Chittick ] about 'grading' clubs so they could be termed ' country' or otherwise, making it easier to place NZ horses when racing over there.
As there wouldn't have been a training centre in NZ further than 100km from a GPO at the time, we were all effectively categorised as 'metropolitan'.
Don't know how that works now, obviously we have GPO's although it is next to impossible to find an ordinary, stand-alone Post Office. The closest one to me is lurking at the back of my local bookshop.