The story of Nephi breaking his bow is realistic in different ways including the effect it would have on Laman and Lemuel.
William J. Hamblin explains:
Most readers of the Book of Mormon remember vividly the story in 1 Nephi 16 of the slack and broken bows. The account is interesting and well told. Imbedded in this memorable narrative are several long-overlooked points that only now drive home the fact that Nephi’s account is right on target.
The symbolic message of the broken bow, first detected by Alan Goff, was highlighted in the March 1984 issue of the F.A.R.M.S. newsletter: “Bows were symbols of political power. One thinks of Odysseus bending the bow to prove himself. An overlord would break the bow of a disobedient vassal to symbolically put the rebel in his place” (see also Jeremiah 49:35; 51:56). That detail is significant in 1 Nephi 16. Nephi’s bow broke, and the bows of Laman and Lemuel lost their springs, but when Nephi fashioned a new bow, making him the only one in camp with a bow, his brothers soon accused Nephi of having political ambitions (see 1 Nephi 16:37-38)– William J. Hamblin, “Nephi’s Bows and Arrows,” in Reexploring the Book of Mormon, edited by John W. Welch (Provo, Utah: FARMS, 1992), Chapter 11
Would we expect Joseph Smith to understand the political significance of making a new bow? Where would Joseph have been getting this kind of information from?