Basically there are going to be anomalies/argument either way you look at it. I could have gone just Townsville and Charters LGAs populations perhaps and that would mean they would have the best ratio, lower than the Knights. I was using the ABS regional grouping though which includes Mackay and Bowen, however if we include Cairns and Innisfail or everything in a 400km radius, then the quotient actually becomes higher and looks worse, as the population increases. Including Mackay in the region increases the ratio a bit but thought it was a trade off.
If we use that same methodology then we could say people travel from Goulburn and Wagga to go to Canberra games so they should be included, or people travel from Taree, Singleton and Port to go to Knights games, or people travel from country towns every week to see Sydney teams play etc, etc.
There is no perfect way to count it. Either way Cowboys and Knights are the best supported teams.