War is the theme at the end of the book of Ether, and Coriantumr is described as one trained in “all the arts of war and the cunning of the world.” It is likely that his opponents were similarly trained.
Coriantumr is also one who will not repent. Verse 17 declares that the sons and daughters of Cohor and Corihor will not repent. Those are two names from deeper in Jaredite history. They are sons of Noah, who was a king who did not follow God. It is quite possible that when Mormon wrote the story of Zeniff’s son, he may have borrowed Noah’s name from the Jaredite record and used it to provide a context to the wickedness of Zeniff’s son.
By invoking unrighteous ancestors, the conflict is given deep roots in Jaredite culture, and deep roots in a people with a history of rejecting God and his teachings. Thus, when they are unrepentant in the last days, it is unsurprising, and a continuation of the influence of an ancestral tradition.