Red Mage as possible new tank class

[Ruminate]

RDM was a melee fighter, but it was never a frontline fighter because it lacked the survivability.

They're frontline mages, not melee fighters. Non-MMO RDM meleed to conserve MP, not because their melee was good. FFXI RDMs were given the Mystic Knight's Spellblade, along with Refresh and Convert, because no one wanted RDM in groups. FFXI Mystic Knights were turned into tanks because Square shot themselves in the foot by giving Spellblade to RDM.