Literary: This is a highly stylized verse. The “fair sons and daughters” is a phrase that is repeated four times. Certainly the phrase refers to descendants, but in this case, there function is to include all of the people of the land. The final “there were none of the fair sons and daughters” indicates that the entire body of the Jaredite polity is unrepentant.
The next stylized part of the verse is the inclusion of the names of Cohor and Corihor. While Coriantumr is a current figure, Cohor and Corihor are probably related to the historical people that we have already seen bearing those names.
Both Corihor and Cohor come from the earliest times of the Jaredite peoples, so that their “fair sons and daughters” are rather certainly symbolic at this point. Corihor is the first of the listed sons who rebel against their father (Ether 7:4). Cohor is also a rebel against family, who establishes a separate kingdom (Ether 7:20). The presentation of these two names from history is meant to describe the two types of people involved in this last war of destruction. There is the current ruling line, represented by Coriantumr, and there is the rebellious portion of the people, symbolically represented by the ancestral rebels, Corihor and Cohor. All of these aspects of political conflict are present, and none of them will turn to the Lord.