MNK, NIN, and DRG don't need to heal the main tank, and taken literally a melee healer would need to be in melee range of the MT to heal the MT. EDIT: Yes, if they can cast spells at range anyway, and they just use melee attacks to generate resources etc, I have trouble figuring out the balance because then you'd have a healer that HAS to dps, something no current healer HAS to do outside of the meta.
To both you and Legion, perhaps I don't have a good understanding of it because I just can't envision it. If they do it and it works, great, I'd love the change in healing pace just like I'd love to see Blue Mage Tank.
