Just back on this Super Rugby AU concept as the 3rd tier, one of the biggest challenges for RA is to keep the younger players in the game, and the way to do that is to offer more competitive professional contracts. Take that a step further, it's the grassroots products from NSW and Qld that need to be the centre of attention to stop them going to league or overseas. Also, to make this comp interesting there needs to be more than 4 teams, so I wondered if a solution is for Qld and NSW to have an age group team (say U21) as well as a open/senior one. Thus, there would be 8 teams as per below:
NSW - mostly club and non-Wallaby Tahs
NSW U21 - mostly academy
Qld - mostly club and non-Wallaby Reds
Qld U21 - mostly academy
Brumbies - mostly academy and non-Wallaby Brumbies
Force - mostly academy and non-Wallaby Forces
Melbourne - mix of club and academy
Drua - mix of academy and PI heritage club
Having written that, maybe something similar to the US college system in that the U21's players can play up to age 23 provided they were signed when under 21, and Melbourne get prioritised with the overflow of NSW/Qld players to help with their rebuild. Once these 'U21' players are on the open market a lot would go to other franchises, but the objective is to keep them in the game/system. Also use the U21 teams as a marketing tool to get a younger audience interested in the game.
I don't think mixing in age grade teams works at all for a comp like this.
If you're doing it to offer more pro contracts to young players then doing it this way creates a massive imbalance for young talent with QLD and NSW capable of offering so many more places and potential game time in the early years. Eventually that opportunity dries up as players age out and plenty have to head elsewhere. Yes there will be some oppurtunity at the Force and Brumbies for them, but they've missed time developing in system in Perth or Canberra and are much more likely to take the money overseas then they otherwise would have been.
If you're doing it for interest in the comp (financial return effectively), I can't see it being worth the cost. Adding a few more teams might help to add a bit of interest overall, but the age grade sides are always going to be more poorly supported than they're state equivalents. Over time that's likely to get worse as the players move through them at a much faster rate.
If there is money for 2 extra sides it would be much better spent on something like a city/country approach for QLD and NSW, with both teams being full sides in their own right. It's going to drive more interest than age grade sides, hopefully with more money coming in as a result and teams that can be built around long term. From a development persepective it's much better aligned with the top sides and doesn't force QLD and NSW into a position where they are incentivised to (and need to) swallow up all the age grade talent.
The alternative if you want a focus on age grade is to run an under 21s comp alongside this. Start contracting the best 18-21 year olds in much greater numbers on base contracts and play them all as double headers with this Super AU comp. That offers better flow through the pathways and gives the age grade players more top level game time. Balancing it with the under 19s might be a bit tricky, but there are options there, the biggest challenge is going to be cost, which with a lot more players contracted will be significant.
All that said I don't think they should be looking to stretch anything in the first few years of this Super AU if it gets up. Run lean and efficient and build a base that can then be built on as needed, probably not until the world cup. Then with that influx of cash and interest RA can build more on what they've already established.