Tigerlaird
The Red Panther
The ship has set sail unfortunately. It would be nice, but it won't happen for a very long time and even then, it will be a brand new composite side with no connection to the SANFL.
If, as planned, it ended up with Port in 1991 (instead of Crows) and Norwood in 1997 (instead of Port) then you could argue that a 3rd team would be closer than the next 50 years.
I think Adelaide should have either;
SA1 Port
SA2 Norwood
SA3 Composite team
or
1 team for Adelaide made up as a composite of the 9 sanfl clubs.
Adelaide would have had an extremely successful team with a huge fanbase if it was a one-team city.