To be fair, AFL's heartland doesn't have mid-sized regional centres like Woolongong, Newcastle, Townsville, or the Central Coast for that matter.. so their focus on the big 5 capitals was sheer necessity. Then when every one of them outside Melbourrne had a team, it was "double down" time.. there weren't many other options.
RL has mid-size locations with teams, which provides decent coverage of the heartland, but coupled with an oversaturated Sydney means we just CAN'T "double down" on all those big capitals like AFL.. which might not be a bad thing.