That's sort of my thinking too. With Arcanist as a DoT/debuff specialist, there's not much room to make a true um... "bimagical" job like SCH traditionally is, even if the handful of job abilities it gets are all heals/buffs. It's one of the main reasons I'm leaning towards exactly what you said -- that we'll see "grimoires" on Arcanists and Summoners while Scholars might wield "tomes" instead. Their class could range anywhere from an oracle/sage type focusing purely on the magical aspects of the job to a tactician/arithmetician type with an emphasis on things like sensory magic.