Actually very cool I had heard about the eel thing but not the full implications of fire stick farming, in fact now that you mention it this sounds like the managed woodlands of north America that the colonists slipped into after the plagues killed most of the natives! cool though maybe they could create the perfect conditions for several mega fauna to survive in this fashion? in Australia cool dudes riding giant kangaroos north America mammoth riders or giant sloth cavalry!!
Diprotodonts at least did co-exist with aboriginal australians for quite a while, so probably. Maybe if it was developed earlier they would have domesticated the megafauna.
There are some claims that the South American Selk'nam did something akin to fire stick farming, but I can't find reliable sources there.