Football was everywhere (e.g. calcio in Italy) The English codified rules for it but that doesn't mean Aussie rules or Gaelic Football are derivitives of the English game.
Medieval kicking games were everywhere, yes, in China and Florence and all kinds of places.
Unless you have some evidence to the contrary, I think it's quite clear they are directly descended. Factors include chronology, similarity of the games and both places being English colonies.
Proto Australian Rules Football predates European settlement of Australia and possibly even European settlement of England.
Marn Grook, marn-grook or marngrook is the popular collective name for traditional Indigenous Australian football games played at gatherings and celebrations by sometimes more than 100 players. From the Woiwurung language of the Kulin people, it means "ball" and "game".
And you're telling me you believe the white Australians adopted and codified this indigenous game instead of one based on English Rugby Football? It doesn't seem likely.
Like I said, medieval kicking games were everywhere, including marn grook, but I don't see any evidence that Aussie Rules is based on it. "Some historians claim" is the strongest sentence in that Wikipedia article.
I'm saying I believe that Australian settlers were heavily influenced by many things that indigenous people did; what to eat, where to find good water, how to manage land, but they rarely acknowledged that influence.
The original version of AFL played by English settlers was a great deal more like original Marn grook than 'modern' codified AFL - the playing area was larger and effectively unbounded (save by the need to score through designated goal areas, etc).
Indigenous influence on AFL creation confirmed by historical transcripts, historian says
Monash University historian Professor Jenny Hocking found transcripts placing Indigenous football, commonly known today as Marngrook, firmly in the Western district of Victoria where Australian rules founder Tom Wills grew up.
"We found in the State Library of Victoria records of a transcription of an interview with [Mukjarrawaint man] Johnny Connolly, who describes actually playing the game in the Grampians region as a child in the 1830s to 40s,"
You're entitled to your opinion but I'd hazard a guess you never grew up playing barefoot football on stony ground with aboriginal teams whereas I did (40 years ago).
Everybody seems to wear shoes now and many of the remote fields have grass now, with a few exceptions:
Unless you have some evidence to the contrary, I think it's quite clear they are directly descended. Factors include chronology, similarity of the games and both places being English colonies.