You can make your preferences to any party, putting the two you don't trust as 11 and 12 if you like, But it comes down to who are the last two standing, and by popular or unpopukar vote, that just happens to be ALP and LNP.
Think about it like a football season. Every team gets to play, but at the end of the season, the top eight play off in the finals. Each finals match, one team is eliminated, until the Grand Final, when the last two remaining teams play off. The beaten teams are eliminated don't get to play again.
Abd GON, could you imagine the commentators calling the match sayimg "Team A is leading by 15 points". No, tthey call the teams by their name. That's not showing preference, and has no impact on the outcome.