I can see something like fencer being a class and from fencer one can be a red mage, which will be a dps/support class and maybe a mystic knight which can be a mage tank of sorts. I can not see red mage being a tank at all. Granted they can just create abilities and make it into a tank but I do no think, they will do that. Someone said this in another post and i'll quote " The devs create classes/jobs based on can this person tank yes/no, can this person heal yes/no, if the answer is no to both he is dps." Which makes sense. There has to be a look and feel to it.. i mean you are equipping cloth and trying to tank a titan punching you in the face..it doesn't feel or look good.