If that's the case then why put a team there?
Its population is under 500k. If its people prefer onionball and fumbleball then there aren't going to be too many people left to support a new NRL club when there are nine within driving distance.
Roosters could convince 5k people from North Shore to attend 12 games at SFS each year if they marketed themselves better. That's just 1% of the population. Add 5k to what they get now and they're near the 20k mark. That's a step in the right direction.
When A league was looking to expand the north shore scored the best in all metrics. Large affluent population in biggest market in country.
North Sydney to central coast team would stack up against Perth etc I'm guessing