Stephen D. Ricks et al. discusses etymology of "Archeantus"; claims that it probably has a Greek origin, not Semitic.
Dictionary of Proper Names and Foreign Words in the Book of Mormon, ed. Stephen D. Ricks, Paul Y. Hoskisson, Robert F. Smith, and John Gee (Orem, Utah: The Interpreter Foundation, 2022), 60
Archeantus
Lehite PN Nephite army leader (Moroni 9:2)
Brief Etymology: the PN ARCHEANTUS is possibly of Greek origin, form the Greek αρχων (archon), “chief civil magistrate.”
Extended Discussion: The PN ARCHEANTUS may be of Greek origin, possibly from the Greek αρχων, “chief civil magistrate”; compare the Palmyrene and Jewish Aramaic word ‘rkwn from αρχων (archon), with the infix -eant/eanc- common to several Book of Mormon names, such as Seantum or Teancum. The name may also derive from the Greek archē, “magistracy; power, dominion” plus the infix -ant. A Hebrew or Semitic origin for this name does not readily suggest itself.
The occurrence of names of Greek origin suggests Hellenic contacts with the western Mediterranean in antiquity. Since the late second millennium BC, Syrians and Phoenicians had trading contracts with the Aegean kingdoms, and in the first millennium BC Greek mercenaries and merchants maintained a significant and ongoing presence in Syro-Palestinian territories, thereby providing opportunities for Greek titles and names to be transferred to the eastern Mediterranean. Alternatively, it is also possible that Greek titles and names may have resulted from cultural contact with the New World from a later period of time, possibly even during the period of Christ’s ministry among the Nephites.