Brissie Broncs = 173,000 ave in Brissie.
NQ or GC, not Brissie = 157,000 ave in Brissie.
Non-Queensland team = 107,000 ave in Brissie.
So if Brissie 2, 3 and 4 are no better than NQ and GC they will still draw 50,000 more in Brissie than any team from the other states. Advertisers sure prefer to have 157,000 sets of eyeballs watching than 107,000.
In Sydney, the highest rating match was Round 12s Parramatta v South Sydney game which rated 259,000. 13.9 million people watched the NRL on Nine in Sydney in 2019 at an average of 197,000 per game.
Matches involving Sydney teams rated an average of 198,000, while matches involving both sides from outside Sydney rated an average of 186,000.
http://www.footyindustry.com/?p=4923
Everything you said is wrong.
If you were to broadcast 2 Brissie teams into Sydney you would get a net gain of 38,000, at the very least, than if 2 non-Queensland teams were shown into Brissie.