Fair call.
The Nationals do have more seats than the Greens but "in order of popularity" was probably the wrong wording.
The Nationals don't contest all seats and are also combined as the LNP in Queensland. Even so, they would be unlikely to get to 12% of the national vote if they did.
Australia only has proportion representation in the Senate (upper house). Each state elects 6 senators based on the proportion of votes they receive.
In the House of Representatives (lower house) you vote for your local member. This is a vote for a single person per electorate via preferential voting. Therefore, there is no proportional representation in the lower house and smaller parties are unlikely to get any seats unless they have concentrated supporter bases (ie the Nationals are a rural party and only ever get seats in rural electorates).
Australia's 4 largest parties are the Labor, Liberals, Nationals and Greens parties (in order of popularity). The Liberals and Nationals are the two major conservative parties and typically form a Coalition together to govern. Labor typically can govern on its own but has also formed a coalition with the Greens in the past.
Due to its proportional system, the Senate has a larger number of parties represented. No government has had a majority in the senate in over 20 years (and even that was the Liberal and National Coalition government having exactly half of the senate seats).
In the latest election, Labor had a landslide victory but still won't have a majority in the Senate. Therefore, despite not having a formal coalition government, they will still need support from other parties to pass legislation.
I just finished The Hair Carpet Weavers by Andreas Eschbach. One of the best first chapters I've read in a long time. Really interesting scifi book that I couldn't put down.