Unless current treads change dramatically I can't see Melbourne being a realistic option for expansion until the late 2020's at the very earliest.
Any talk of a second Melbourne team entering the competition before 2028ish is just bravado of the kind that saw GWS enter the AFL before 2025ish.
The problems with your logic here are numerous.
For starters take the "extra fans" bit, in the case of cities that already have clubs there's already a directly accessible club for fans of the sport to support and adding another club doesn't just magically generate new fans for the sport, the people that will be interested in supporting the new club are already fans in some capacity.
So what needs to be established before a second team is put in place is how much of an impact on the original clubs fan-base would a second club have and whether or not there're enough fans of the sport in general in the city to support two clubs. Otherwise you may end up effectively just cutting one clubs supporters base in two to support two club, which creates the classic two weak clubs instead of one strong one.
You also ignore the possibility that there may not be demand for a game every weekend in Melbourne (or any other city) and also that for a derby to be valuable their needs to be either a vehement sub-cultural divide within the city or a tribalised geographical border within the city otherwise the derby isn't seen as a big deal as all a derby is is a rivalry that takes place between two clubs that happen to be from the same city, if there's nothing to create a rivalry then there's no rivalry and if the clubs in question aren't rivals there's no derby.
I don't really understand your anti Adelaide stance, and I don't think I want to. So I'll just address some points that have been bolded.
Firstly, there is no reason why we'd have to choose between expanding to Adelaide and Melbourne, within a 20-30 year time period we could do both.
Secondly, as I very briefly addressed above derbies don't always work, aren't always worth the money it would take to put them in place, aren't a necessity and aren't always possible to create.
Thirdly, it wouldn't take 30 years to prepare Adelaide for an NRL team, provided that more funds and resources were given to the NRLSA and professional people picked by the NRL were instilled to oversee the preparations, it'd take roughly the same amount of time that it took Perth to get ready for an NRL team, so only the better part of a decade.
Backward argumentation like "faking one-eyed city that supports one code" is incredibly simplistic and if taken seriously could be used to shutdown any expansion opportunity.
Finally, SA is a valuable market, admittedly not as valuable as Brisbane, Auckland, the rest of NZ, Perth and Melbourne, but still valuable none the less and it's worth placing a team in Adelaide to tap into that wealth. Realistically A second Auckland team and a second Melbourne team are a decade and a half away from being viable expansion options and in the meantime we have three areas (Brisbane, Perth and a Wellington based NZ2) that need and can sustain clubs. So we've got an odd number and need another club to makeup numbers unless we're satisfied with a bye (which I am not as it's a waste of potential) and the next largest market that could support an NRL club within the next 30 years is Adelaide! As I stated before with the right support they could be ready to go within the a decade and they offer the NRL a truly national footprint, the opportunity to be able to create equal conferences (when we inevitably need to) on top of the a fore mentioned access to a valuable market.
Also if we choose to expand to Adelaide, Perth, Brisbane 2, NZ 2 and in a decade or two Auckland 2 and Melbourne 2 instead of a relocating to any of them, that leaves us with roughly 3-5 Sydney based clubs that will eventually need to relocate for the competition to be sustainable, that we can arrange relocation to smaller markets (such as the CC and CQ) that couldn't support NRL clubs on their own, thus giving us sustainable constant access to 3-5 more markets on top of the aforementioned markets that we wouldn't have whilst still sustaining an even number of clubs for easy scheduling.
Unless realistic expansion opportunities in Asia and the South Pacific come a lot earlier then I or anybody else anticipate, having a team in Adelaide is the best way forward without over diluting markets such as Brisbane, Melbourne and NZ with third clubs before both the NRL and the markets themselves are ready for it.
Look, i bolded a couple of your points because you have too much trivial amounst it, without any facts or truth.
Yes it is simplistic, because this works. And it is the reason why derbies work.
I mean how much faking proof do you need.
Manchester united, Manchester city.
Sydney FC, Wanderers.
Essendon, Carlton
Collingwood, Carlton,.
Melbourne city, Melbourne FC
Swans Giants
They are all working and will grow.
So it is now back to you, show me where derbies dont build support and crowds and fans. Show me.
South OZ a valuable market. ?? Really.
It is a city of 1 million, and has grown little over the last 2 decades.
It is hardly talked about, they just spent a faking fortune on a round ground, (so investment in a rectangle ground wont come easy).
I mean shite, it took nearly a decade for the Storm to get out of a round training track and into a new 30 thousand stadium.
They could not build a bigger one because Melbourne have in place a monopoly for round grounds and stadiums because of a clause for etihad.
As i pointed out in my city and stadium rant yesterday.
Melbourne has shite stadiums for rugby league, union and even soccer to use. (big grounds over 30 thousand)
We should be looking at now the use of the new stadiums in Perth and Adelaide.
For big games.
As for giving them a team. again, what is the sense of games that need to be played in rectangle grounds, played in round grounds where our atmosphere is lost.
This goes back to my lack of marketing and promotion managers.
I mean the AFL would never play a game on a rectangle field, ? no, they are not that stupid.
We are "that stupid", we do it all the time and whinge like crap because it is souless. (SCG, ANZ, round grounds)