Depends how closely you copy the brand TBF.
In theory you could keep it close enough that it could confuse people without it being similar enough that it infringes IP laws. You could, for example, call the team the Grizzlies, Bruins, Ursa, Sun Bears, etc, create a logo that's aesthetically different from NS, make some minor changes to the colours, and get away with a bears brand without it being the Bears brand if you know what I mean.
IDK why you'd do that in Perth's case, it's not like they're going to fool anyone who matters into believing they're affiliated with NS, nor do they need to be fooling anybody anyway, but you get the point.