Stating the obvious, but Sydney's rugby league clubs were born and admitted into the league at times which reflected the growth of within the Sydney metro area itself. in the early years, the NSWRFL was overwhelmingly represented by clubs from areas we'd consider inner-city or within 10km of the CBD. Of the 11 clubs that existed at one point or another in the foundation years - Annandale, Balmain, Cumberland, Eastern Suburbs, Glebe, Newcastle, Newtown, North Sydney, South Sydney, Western Suburbs - only 2 were outside this imaginary peripherique. University were introduced in 1920 and lasted a couple of decades, but the real expansion into the 'burbs began with Saints in '21, then stepped up with Canterbury-Bankstown in the 30s, Manly & Parra in the 40s, and Cronulla & Penrith in the late 60s.
Obviously, the number Sydney-metro based teams is on the high side for a national competition. Little did the grandfathers of the game know that the game was to go national. Successive administrations have sought to rationalise the number of teams but the structure as it is now is far from ideal yet at the same time required to maintain the fabric of the game.
If one was to hypothetically start up a new rugby league competition today based on population centres and the popularity of the sport, there is no doubt that the make up would be significantly different.
Based on an 18-team structre, it would/should consist (IMO) of:
Sydney (east, city, lower north shore & inner west)
Sydney (southern suburbs)
Sydney (northern suburbs)
Sydney (west, north-west)
Sydney (west, south-west)
Brisbane
Brisbane
Gold Coast
Newcastle
Melbourne
Adelaide
Perth
Canberra
North Queensland
Illawarra
Central Coast
Sunshine Coast
Auckland