thats one of those great myths lol. AFL clubs draw support from all over the city, not just their namesake suburb. Carlton membership 80k, Carlton population 7k.It certainly helped them attracting attendances with many of their teams closely bunched together. Thats why centralised stadiums works for aerial ping pong in Melbourne.
In the NRL, hypothetically, if Newtown and Norths were still in the comp, then there home ground could've been Allianz, due to close proximity of NSO and Henson Park.
7 of sydneys 9 clubs are 20km or less from Commbank or Allianz. Just saying lol.