There are already some existing threads about this, but they were posted to the General Discussion board instead of the Localization board. Hopefully this issue will get more visibility on the Localization board.

The extreme primal weapon names are all named after FFIII weapons. In FFIII, White Mages used the Elder Staff and Black Mages used the Omnirod. In FFXIV, they're reversed—the Black Mage extreme primal weapon is Elder Staff, and the White Mage extreme primal weapon is Omnirod. Note that this does not appear to be a translation issue (as the Japanese names are the same as in English), but a lore issue.

See also:
http://forum.square-enix.com/ffxiv/t...ature-reversal