Queensland does make a certain amount of sense, but you ignore Sydney at your peril... the population of Sydney will hit 5 million this year, versus about 2.1 million in Brisbane. Ideally, Ithink you'd want to Super Rugby teams in both.
Also, the ARU don't want to move the Force to Sydney - that was just a thought bubble from a former Force executive who'd given up hope on them. But the Force have carved out a decent niche in the Perth market, so it's not something they'll be considering
There are obviously too many NRL teams in Sydney, but Rugby needs to carve out a fan base that extends beyond just the east and north shore, and so it must do something about the west.
Personally, I'd like to see the Waratahs split their matches across the city - say have 4 at Moore Park, 3 at Parramatta and take one to Penrith too. But that doesn't appear to be something they're willing to consider, so the next best option is having a cross town rivalry.