Looking at the numbers in Frontlines CAN be pointless. For example healing between the 3 healers varies a lot cause some rely heavily on shields that aren't counted as healing while some healers might be spamming regen effects on parties and constantly gain tons of healing. Also healing can be party dependent for example a WHM who just keeps AOE healing a full 8 player alliance that is constantly in combat can reach over 3 million healing in maps like Onsal while someone might have a party that avoids fighting or is split around everywhere in the map so you wont be able to in any way compete with the same numbers. Also for the damage part the healer can do alot of damage by casting Glare's and other AOE while using only OGCD spells to heal. Being really comfortable with your job and playing with a premade party helps too