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.
I’m still getting used to Lemmy. But is there a reason we can’t see the Aussie zone server in the Jerboa android app?
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.
If you don’t have an account it seems it just uses lemmy.ml by default in Jerboa. If you want to use a different instance, you need to signup and then login.
For adding content from other instances, you can likely find it with https://browse.feddit.de/ (the built in communities search shows some but not all instances). Then e.g. if you’re using lemmy.ml adding cricket community from aussie.zone:
https://lemmy.ml/c/cricket@aussie.zone