* https://mgnsw.org.au/wp-content/uploads/2019/01/map_col_high...
* https://www.abc.net.au/news/science/2016-09-22/world-first-s...
This recent genetic based view replaces the "gut feeling" view akin to yours that was long pushed by Quadrant et al.
Read article, chase up the papers, evidence says "no".
The Tasmanians and the Noongars (Southern most to east, southern most to west) have genetically been in place a long time and had no one to replace.
The article mentions "genetic diversity" between east, west, centre, north, south, etc - that comes from not mixing.
"But surely..." <-- gut feelings? You should joinn Quadrant.
> If a tribe moved from southern Australia to the north and replaced another tribe
Do you have any evidence of that?
> who gets the land now?
There's a wealth of material on Mabo, Land rights, Native title, et al that address all that - if you're generally curious it's there to read.
eg: starting with, say https://aiatsis.gov.au/explore/mabo-case
Otherwise, how would you decide who gets which part of the world?