Quote Originally Posted by Ceallach View Post
  1. Handbell
  2. Unreliable geomancy
  3. Mage robes
Yeah, that totally looks tank-worthy to me.
The picture I linked was from Final Fantasy Explorers, where Geomancer is a support/tank, arguably one of the tankiest melee classes in the game with their mighty glacier tendencies, HP and clubs/bells.
Also worth noting that Geomancers in Final Fantasy Tactics, one of their more popular incarnations, couldn't wear heavy armor but they could wear some of the other kinds of best armor, shields, their HP growth was 3rd highest in the game (tied with Knight and Dragoon!) and their HP multiplier was 4th highest, drastically higher than any other mage class and only 10 behind Knight/Dragoon.

All this isn't implying that I think it has to be a tank or anything, but you speak as if there's NO precedent, when there's clearly some.