In addition to Jacob 5 being difficult to follow, it is also remarkably accurate. John Gee and Daniel C. Peterson explain:
[Jacob 5] purports to be the work of an ancient northern Israelite author, living between 900-700 B.C., about olive growing…Almost every detail it supplies about olive culture can be confirmed in four classical authors whose authority on the subject can be traced back to Syro-Palestine. Zenos’s parable fits into the pattern of ancient olive cultivation remarkably well. The placing of the villa above the vineyards [Columella, Rei Rusticae I, 5,7] means that, when the master gives instructions to his servants, they have to “go down” into the vineyard (Jacob 5:15, 29, 38). It was also customary for the master of the vineyard to have several servants (cf. Jacob 5:7,10-11,15-16, 20-21, 25-30, 33-35, 38, 41, 48-50, 57, 61-62,70-72,75). [Cato, De Agri Cultura 10; Varro, Rerum Rusticarum I, 18.] When only one servant is mentioned in Zenos’s parable, the reference is most likely to the chief steward. Likewise, Zenos’s mention of planting (Jacob 5:23-25, 52, 54), pruning (Jacob 5:11, 47, 76; 6:2), grafting (Jacob 5:8,9-10,17-18, 30, 34, 52, 54-57, 60, 63-65, 67-68), digging (Jacob 5:4, 27, 63-64), nourishing (Jacob 5:4,12, 27, 28,58,71; 6:2), and dunging (Jacob 5:47, 64, 76), as well as the fact that dunging occurs less frequently in the parable than the nourishing, all mark it as an authentic ancient work. The unexpected change of wild olive branches to tame ones (Jacob 5:17-18) would have seemed a divine portent to our ancient authorities. [Theophrastus, Historia Plantarum II, 3,1.]
Even more striking, for Joseph Smith to have made up the parable from these classical authors, he would have had to read all four: Theophrastus is the only one to discuss the differences between wild and tame olives, the tendency for wild olives to predominate, and prophetic use of the olive tree as a sign. [Romans 11:16-24 does mention wild and tame and grafting, but nothing about the fruit or the purposes thereof. A casual reading of Paul leaves the impression that it is as easy to be one way as the other.] Varro and Columella are the only ones to acknowledge the Phoenician connections. Cato and Varro are the only ones who discuss the servants’ roles. Cato and Columella alone note the placement of the villa above the groves; Varro is the only author to discuss the “main top” in association with the “young and tender branches” (cf. Jacob 5:6). Yet Joseph Smith probably did not have access to these works. And even if he had, he could not read Latin and Greek in 1829. Theophrastus’s Historia Plantarum first published in English in 1916, [Theophrastus, Enquiry into Plants, trans. Arthur Hort (London: Heinemann, 1916)] and no part of his De Causis Plantarum was available in English until 1927 [Robert E. Dengler, … Ph.D. Dissertation, University of Pennsylvania, 1927]. While English translations of Cato, Varro, and Columella were available to the British in 1803, 1800, and 1745 respectively [Thomas Owen, M. Porcius Cato concerning Agriculture (London: White, 1803), …], it is hardly likely that they were widely circulated in rural New York and Pennsylvania. Joseph Smith could have known nothing about olives from personal experience, as they do not grow in Vermont and New York. Can it reasonably be supposed that Joseph simply guessed right on so many details? And even if he somehow managed to get the details from classical authors, how did he know to put it into the proper Hebrew narrative form? [The narrative of Zenos follows the Hebrew narrative pattern as laid down by Robert Alter, The Art of Biblical Narrative (New York: Basic Books, 1981).]
Even if Joseph Smith had somehow gathered the details of ancient olive culture from someone who knew it intimately, he would still have had no plot. [Zenos’s plot is much more complicated than Paul’s, and if Joseph Smith is adding to the plot, it must be explained how he got the extra details … and made them fit in with ancient olive lore.]– John Gee and Daniel C. Peterson – Graft and Corruption: On Olives and Olive Culture in the Pre-Modern Mediterranean
How could Joseph Smith have been so well read? Where would he have been getting all this information from?