The commanders in this verse are not the same as the officers; they are men who would be appointed to be in charge of the various units that would be formed after some men had gone back home, for the different reasons given above. For the size of the units, see 1.15, where the same Hebrew word for commanders is used.

Shall be appointed: the Hebrew verb is the third person plural of the active voice, literally “they shall appoint.” In this context the subject or agent may be the officers (so New International Version, Contemporary English Version); for example, “they will appoint commanders.” Alternatively the third plural may be used impersonally, which is often done, with the meaning “they [the commanders] shall assume command” (so New Jewish Publication Society’s Tanakh, New Revised Standard Version). Or even the passive sense, as in Revised Standard Version and Good News Translation, may be intended. The meaning expressed by New Jewish Publication Society’s Tanakh and New Revised Standard Version is to be preferred.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .