I've been doing some more reading on how the city names are placed and going back to the Waze Wiki: http://www.waze.com/wiki/index.php/Time ... Boundaries
It ways that

This becomes fixed as more roads, closer together, are given the city name.

Does this explain why Ngatea appears in exactly the right place and Patea didn't (before nzhook forced the placement by removing the city name from surrounding roads)?

Ngatea has a higher concentration of roads in the town centre so my question is - does that influence the placement of the city name on the map?

This is Ngatea: https://world.waze.com/editor/?zoom=3&l ... TTTTTTTTFT

Is Matamata the same? The name appears in the centre of the town but I doubt this is the centre point of all roads using Matamata in the city name.