Re the US NFL example: let’s not forget the large number of their players that go off the rails at some stage of their career. Encyclopaedias could be written about drug abuse, and domestic violence in those leagues.
They have is a long history of players being treated as expendable commodities. Pay them big bucks then spit them out. Young men, high testosterone environment, high incomes, with free time and public adoration - what a recipe for trouble. The NFL, EPL, US Baseball .... the AFL should be careful and cautiously study those leagues a bit more closely rather than aim to be more like them.