If you were starting from scratch you'd have
6 Sydney clubs
3 Brisbane clubs
2 Melbourne clubs
2 Perth clubs
1 Adelaide club
in terms of metro split. Thats a strong 14 club city comp then you can add in the larger regional cities/NZ on top of that. What weve got is just a historic hangover of evolving a local comp.
Not if it is a rugby league competition. Merging Sydney & Brisbane comps together would result in strongest representation in the strongest league markets. Throw in Melbourne for grand final audience & Auckland for sky deal & that's most lucrative scenario.