Greens get a steady 15-20% percent of voters just about everywhere around the nation (except Melbourne where it's higher). Not enough to win a seat, but enough that their preferences are extremely valuable. But Greens have nobody else to give those preferences to - at the end of the day the Liberal party is less compatible to Green policies than Labor is.
It would actually be a strong signal one election for those preferences to go somewhere else. Labor won't get elected without those preferences - but they seem to take them for granted. One Nation do it from time to time and they only get 2-5% of the vote. Some elections, they give their preferences to the non-sitting member (Liberal candidate if sitting member was Labor/Labor if the sitting member was Liberal). One election, it was enough to tip the balance.
15-20% of the vote is plenty enough to get representation in the senate, of course.
Greens need a re-brand. They are seen by older voters as one-trick ponies. Caring solely about the environment and not having any policies on anything else. That's not true of course, but their marketing sucks. If they could actually articulate their positions to voters somehow, I think far more voters would realise they align with Green policies.
TL;DR: all the experts say "yes".
I don't have a strong opinion on the topic, but my non-expert opinion is "probably not". It would have been outright "no" before reading this article, but some of those arguments were actually persuasive.
It isn't that I want a weak military, it's that I see so many priorities the government can be spending on and defense still isn't at the top of that list for me.