In his editing for the 1837 edition, Joseph Smith initially decided to emend the rather awkward “unto them in me” to the simpler “unto me”. Of course, the intended meaning here is that these missionaries’ examples of godlike behavior (“good examples in me”) will be shown to the Lamanites.
Ultimately, this emendation was ignored in the actual 1837 edition, probably because Joseph himself decided that the emendation would inappropriately change the meaning.
Basically, what we have here in Alma 17:11 is a case of a displaced prepositional phrase. If we shift the placement of the prepositional phrase unto them, the intended meaning becomes more obvious; there are two possibilities:
that ye may shew forth unto them good examples in me
that ye may shew forth good examples in me unto them
The original text, however, allows prepositional phrases to be placed in unexpected positions. For some examples, see under 2 Nephi 25:6; for a general discussion, see under displaced prepositional phrases in volume 3. The critical text will maintain the original word order here in Alma 17:11 (“that ye may shew forth good examples unto them in me”).
Summary: Retain in Alma 17:11 the original reading with its difficult placement of the prepositional phrase unto them (“that ye may shew forth good examples unto them in me”).