How did you level your tank?

[Sida]

As for my healer (SCH), I just spammed dungeons. I am doing the same to level my tank (WAR) but compared to healer, it's taking relatively longer time. Three or four runs were enough to get me one level but as a tank I need seven to ten runs to level up

Is the EXP gain for tanks low on purpose to make them do more dungeons?
Or am I doing something wrong..

Did you level your healer right after you'd played on your bard a lot on maximum level? That would have cumulated you lot of rested exp during the time you were on max level so it didn't get used, and since doing dungeons without any roulette mainly deals it's experience from kills, the rested exp buffer can nearly double a dungeon gain.