Here the 1841 British edition accidentally omitted the repeated definite article the in “the sword or the scimitar”. This variant has been followed in all subsequent LDS editions. The use of the repeated determiner is a Hebraistic characteristic of the Book of Mormon text and should be restored wherever there is textual evidence to support such repetition. When we consider all other conjoined examples of sword and scimitar, we always get repetition of either (1) the determiner or (2) the preposition if there is no determiner:
Thus the text consistently prefers some repetition when sword and scimitar are conjoined. For another example of the repetitive the, see the discussion under 1 Nephi 17:22 (which deals with the conjoining of statutes and judgments); also see the general discussion under conjunctive repetition in volume 3.
Summary: Restore the omitted the before scimitar in Alma 27:29, thus making the text consistent in its repetitive structure for all conjuncts of sword and scimitar.