The imagery in these two verses is one of contention. While it might be any contention, the specific context of these verses is not military, but verbal. In verse 8 the servant says of his adversary "let him come near me, and I will smite him with the strength of my mouth." This is not necessarily a physical battle that is being fought, but a battle nevertheless. The servant is reminding us that not all attacks on our souls are physical, and that the war of words contents for our minds which can guide our hearts. Even in this arena, the servant is confident. As he noted in verse 4, God has awakened his ear to understand the "learned" and he is equal to the task.
Meaning for Jacob's audience: Once again, the possible context of a newly formed group highlights a subtext in Isaiah. If there is a conjoining of peoples, it is certain that the newly entered group would have come from a different religious system. While they were adopted into Israel from all indications (or at least from the lack of contrary indications) they would nevertheless have had a history of understanding the world from a very different world view.
Later in the Book of Mormon we will encounter Nehor, who preaches convincingly another philosophy. Perhaps in these verses we have a context where some of the same was present in Nephi's young group. Perhaps these verses serve as a reminder that the Lord God is equal to philosophical debates?