The Bulldogs were committed to take one game a year to Adelaide but stopped after 2 years because of a money dispute with SACA. The Sharks did it before that for a few season. There hasn't been any mention of bringing other games here to replace which is disappointing, I think the NRL shold have stepped in to make it happen.
It was the AFL who stepped in to ensure it didn't happen.
I think it could work like the Melbourne model has, from the top down. Whilst I agree the grassrootslevel up is better, I just don't think it will work in this environment, which is similar to Melbourne's. When kids have the top level to aspire there are going to want to play the game. At the moment they all want to play AFL or soccer.
You have to understand the context that Melbourne (and Adelaide Rams) where created. It was only because News Ltd wanted teams in those areas at the time. If you were planning it properly, you would never allow that situation to occur.
If you want a successful club, with lots of involvement from the community, the grassroots level is the only way to go. But the time to do this is now. It will be another 5 or so years before the area can be in the running for a team, and by putting in the hard work now, getting those programs running, either by speaking with ARLC to get funds and talks with the SA Govt to get the game played in schools (Even if it's just League-Tag to start with in an Aus-Kick 6 week program), you will find interest in the sport picking up, which may translate into more participants in junior comps, and when that happens more and more teams will spring up, improving the quality of the league.
I do think the that ARLC needs to look at how the State Leagues interact (which is nil currently). You could make a national reserve grade comp, where you play in smaller conferences depending on how many teams you actually have, so if Adelaide has 8 teams, two conferences of 4 teams to reduce costs if you play your more local teams, with the winner (or even both of the grand finalists) of the whole comp going into a knockout comp to play other teams who met similar criteria. It would also be another opportunity for the game to make some money if that stage of the comp could be televised on Foxtel via a game of the round type situation (or even getting someone like the ABC/SBS on board to show that areas team for free). Best 16 teams would only take 4 weeks to happen, if timed to finish at the same time as the NRL finals, the final could be played on grand final day. The best part is that lower rated comps such as Vic, WA and SA would have an opportunity once a year to play higher ranked comps. A break down of something like 4 NSW Clubs, 4 QRL clubs, 2 WA, 2 VIC, 1 SA, 1 TAS, 1 NT, 1 SA (the numbers would change if the quality of a comp improved) represented could really revitalise the game at this level (and who knows, get a little more following of the game at this level).