I think we should keep in mind that the Athenians were drama queens and inserted themselves into litterally fucking everything when they got the chance.
Deposits of Tin and copper are very rarely co located, in order to have a successful bronze age you need vast trade links where as if your using just copper that requires less trade and less sophisication.
I think were talking bronze age culture sophisitcated at most, with me putting a bet that they most likely had copper tools instead of more advanced bronze ones.
Humans have been around for a long time and having adventures and living and its likely we had smaller city states and the like pop up every now and then before officially recorded history.