Your ignorance of history is astounding, Schizm.
Go find me your evidence. There is no evidence of Roman occupation in those lands. The Chinese dynasties overspanned the Roman ones, and they have a continuous line of Kings, all recorded in their scrolls, graves, and palaces. There was no corruption of Chinese to Latin, nor any exchange of characters. The same with the Americas, Australia, the Pacific Isles. AND, come to think of it, the Scots, of which I am a descendant. The Romans built a wall to enclose them when they could not be conquered. Are you saying that Rome occupied our current known world without bothering to civilize or tax the natives? How unlike them.
How did the people get there before the Romans? They walked. While there were still land bridges. And as far as I can tell, the Aborigines in Australia were always just there. Walkabout.