Augustus
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Sooner or later, they would probably have industrialised themselves via trade and interaction. It's not like countries who were not colonised remain idyllic natural paradises to this day.
One thing that they would want to trade from the Europeans would be industrial era weaponry. The tribes who traded more and industrialised more effectively would have better weapons, and throughput human history, having more powerful military forces than your neighbours has been a very big incentive to take their lands off them and increase your own power.
Military tech is the ultimate in 'keeping up with the Joneses', you need to do whatever is necessary to keep pace with those around you.
One thing that they would want to trade from the Europeans would be industrial era weaponry. The tribes who traded more and industrialised more effectively would have better weapons, and throughput human history, having more powerful military forces than your neighbours has been a very big incentive to take their lands off them and increase your own power.
Military tech is the ultimate in 'keeping up with the Joneses', you need to do whatever is necessary to keep pace with those around you.