If everyone beats Fire and Spirit from now on, the table will look as follows when excluding all other matches:
Oval 9 (from 7)
Brave 9 (from 7)
Birmingham 8 (from 6)
Rockets 8 (from 6)
Manchester 8 (from 6)
Superchargers 5 (from 6)
That would mean Brave v Oval is a straight shoot-out for one place. The loser will realistically be out.
Rockets v Birmingham, and Rockets v Manchester would both go a very long way in deciding the other two places.
The other two matches are Superchargers v Manchester, and Superchargers v Birmingham. Because of the above head-to-heads, those matches would likely be no use to the Superchargers (to get through on 9 points realistically requires Spirit or Fire to take points off others). But they're of huge use to their opponents.