“There were only six original women,”
Actually, there may have been a lot more. The mitochondria are only passed from mother to daughter. My grandmothers had 5 daughters and one son on one side, and 2 sons on the other. The 5 daughters had 8 sons and one daughter. The one granddaughter had two sons. End of the line for that mitochondrial DNA. So over the millenia, a lot of women never passed on their mitochondrial DNA.
Good point. It could have been six tribes or “nations” if each tribe or nation had a single maternal ancestor (which at some point seems likely). It doesn’t mean only six women showed up.