Rather than fragmented groups, get your Australiana posting in at the Aussie Zone Communities. No affiliation other than living in Australia.
Has cities, sports, politics so far and will add more as needed. It even has Perth and thankfully no Tasmania.
If it’s the first time searched from your instance, it takes time to find. Couple that with the server load makes it even longer.
Search using the search function and put in a community like !australianpolitics@aussie.zone, the whole url, and wait till it appears. You can go back to search and search it again after doing something else.