However, the observation is true. Sports in this part of the world
do seem to like the US franchise name system. I guess it's merely a
form of making nicknames (which we have in England) more official -
but I did chuckle when I first came down under and heard
All Blacks, Black Caps, Tall Caps, Silver Ferns, All Whites,
Black Sticks (... did I miss any) from NZ;
Ollyroos,
Matildas, Joeys etc from Australia. Of course, the reason why
there are official names is that you can then copyright their use.
I am sad to see that Arsenal are trying to do the same thing now in
England. They have copyrighted the use of the name The Gooners and
are enforcing it. The stupid thing there is that the name was
invented on the terraces and has been used informally like that for
decades.... the only thing sadder than that was when Victoria
Beckham tried to take sole rights on the use of Posh and tried to
take action against Peterborough fan clubs (though I never knew if
that was actually true or just a tabloid wind-up.)
Those New Zealand teams all copied the All Blacks, who gained that
name back in 1905 when they were touring in the UK.

Nothing American about it.
The Wallabies and Springboks also got the idea from the All Blacks
and named themselves after local fauna for their UK tours.
All of those other Australian teams then copied the Wallabies.
This was long before anyone cared about American sport.