There's actually quite a few hypotheticals. And none of the spots are settled.
On the NZ/Cairns side of the equation...
If...
Perth beat NZ today, Cairns finish 1st. Regardless of other results.
If...
NZ beat Perth today, then NZ beat Cairns by 25 or more, NZ finish 1st.
If NZ win both, but by less than 25 to Cairns, Cairns finish top.
If...
Cairns beat NZ, they finish top (obviously).
On the Adelaide/Perth side of the equation...
If...
NZ beat Perth today, Adelaide beat both Perth and Wollongong (by any margin), Adelaide finish 3rd.
If...
NZ beat Perth today, Adelaide beat Perth by 28 or more, then regardless of the Wollongong result and Townsville result, Adelaide still come 3rd.
If...
Perth beat NZ today, Adelaide beat Perth by 28 or more and beat Wollongong, Adelaide finish 3rd regardless of the Townsville result.
If...
Perth beat NZ today, Adelaide beat Perth by less than 28 and beat Wollongong, Perth need to lose to Townsville.
If...
Adelaide lose to Wollongong, Perth need to lose all 3 of their games, or lose 2 including by Adelaide by more than 28.
If...
Perth beat Adelaide, they finish 3rd (don't think I covered that).
If...
Adelaide beat Perth by 27 and they end up on the same amount of wins... umm... I assume it goes to percentage, which means Perth finish 3rd.
Same deal with NZ by 24, Cairns still finish top.
Think that covers all the bases.
Plenty of things can still happen.
Just, out of interest, Adelaide can still conceivably have a home Grand Final series...
If we beat Perth and one of the possible outcomes happen for us to come 3rd, then we beat 2nd and Perth beat 1st in the first round of the playoffs.
I'd give it about a 75% chance that Cairns finish first, NZ second, Perth 3rd, Adelaide 4th though (pre-playoffs, not willing to predict who wins round 1).