The reason so many died in Sydney in the first 50 years was mostly diseases brought over by the convicts. The availability of rum to women for sex with whites also caused social problems.
The flu and venereal and a host of other common diseases like chicken pox that most whites survived killed the natives better than guns, but more slowly and painfully.
But nothing that was reported by the British and kept mostly secret could exonerate the allowance of whites to kill natives for minor thefts.
Here is a scenario repeated thousands of times in every colony in the first 50 odd years.
The Natives were usually friendly and curious about these strange people. But when the whites brought in animals and started to grow crops, they--- who had a culture of sharing assumed--- they could come and collect potatoes or an animal like a sheep.
The white settlers became enraged and severely injured a black or killed him. The natives then marked the white and when the opportunity arose they killed him.
The whites then gathered a posse and whoever they found men,, women and children slaughtered whoever they found. There were occasions where hundreds were murdered for the life of a white and the powers that be turned a blind eye to what was going on.
Only after several decades did some whites get hanged for killing large numbers of natives—something covered up from the people.
