yeah. I know what happened. This is more an alternative thought by all parties in hindsight.
The VFL would not have wanted 18 clubs, those leagues would not have wanted to pay licences. St.Kilda would not want to re-locate etc etc. What needed to happen was all parties involved be shaken up by a different thought patterns to work together. As a result of not doing that, we are where we are at.
I think this would have been a better outcome for virtually all except St.Kilda.
Hard to know whether the WA and SA clubs would have been sustainable. Port Adelaide was really the only club across both states that would have had the supporter base to compete with the big Melbourne clubs, and even they were probably more like a mid tier club. The next 5 or 6 from WA and SA would have been roughly similar to North or Fitzroy at the time. Perhaps they could have grown their support base, but they would really have needed a long period at the top level to do that which would have been extremely difficult to achieve.
Consequently it would not have surprised me to see the bottom 4 - the relegation zone in your model - consistently filled mainly by those WA and SA clubs. They then get replaced by other WA and SA clubs and the problems remain.
Personally I like the Elliott model if we're going to look back in hindsight. Basically the biggest half a dozen Melbourne teams + composite teams from other states. It would have been a far more balanced league than what we ended up with.