The biggest rivalry is between Auckland & Wellington. There is a rivalry between Christchurch and Auckland was well. But that doesn’t mean Wellington and Christchurch will combined against Auckland as they have a rivalry with each other as well.
Nobody said that they would... In fact one of the major points of my posts was that no matter what you call the teams you aren't going to get masses of people from multiple of the major markets in NZ supporting a couple of teams that don't directly represent their market once you break the Warriors monopoly on all of NZ.
Hold up, I thought you weren’t claiming to be an expert but now happy to push your opinion as fact?
Got it confirmed by a few people much more in the know of than either of us ever will be.
What they said was that Auckland vs the rest is an overly simplistic way of putting it, but that everyone outside of Auckland wanting to get one over Auckland is definitely a major cultural force in NZ.
That though North Island vs South Island could hypothetically work as a rep game similar to SOO, that having them as the two NZ clubs in an Australian comp would be the equivalent of an NZ comp creating a singular team called "Eastern Seaboard" to represent all of NSW, Victoria, and Queensland, and expecting people from Melbourne, Sydney, and Brisbane, to support them en masse... In other words, the idea is a fanciful pipedream at best.
They also supported my suspicion that if you did create NI and SI teams that market pressures would inevitably force them to become de facto Auckland and Christchurch teams in practice.
Besides that they also said that unlike in a lot of countries where there are strong rivalries between cities that sports can easily capitalise on, that there isn't really a money rivalry in NZ sport generally speaking, and that in NZ the biggest rivalry really depends on the history within the sport, on the success of teams at the time, and other factors as well.
That for the most part Wellington is a bit of graveyard for pro-sport in NZ, and that even by NZ standards Wellington sides are often shaky prospects commercially and tend to be poorly supported per capita, but again there are outliers and it depends on individual circumstances.
Finally they said that if the NRL is serious about taking a significant slice of market share from the NZRU, and truly challenging the All Blacks, that it'd require market coverage and that will require more than two teams, that breaking the current monopoly but allowing the duopoly to become the status quo in the way that the Warriors monopoly did would badly hurt that endeavour, and that branding practices like having a "New Zealand" team, or NI and SI teams for that matter, slowly reduce it's target audience as new clubs are introduced would alienate people.
In other words if the NRL are serious about the NZ market then they need to be prepared to bring clubs into most of the major markets in quick succession after the second club is introduced, and that no matter what they do changing the Warriors brand to represent smaller regions will inevitably alienate portions of their fan base, particularly amongst those that resides outside of Auckland, and the NRL will have to accept that outcome if it's ever to grow in NZ.