Must be a case of revisionist history, almost certainly. How much may be unclear.
Does sorcery exist beyond Earwa? A curious thought. What IS the Onta, how do you see it, and how does that let you manipulate it. Does that interaction of the meta-real and the real only occur in Earwa? And even if yes, just Earwa, then how would the Inchoroi have known before they crashed?
Ostensibly they were in a hurry. Their ship was in disrepair, they couldn't even land properly, yet they came barreling in anyway. To me that suggests they were either fleeing somewhere that over matched them, or they were pretty damn excited to land. How did they know though...