Well, it's a bit hard to judge given the fact both Jobs in Eorzea are virtually extinct, especially SMN, so whatever personality traits might have been standard for practitioners of those jobs in ages past probably is no longer relevant.

One thing though about SMN - although it's unclear about Tristan, given the fact he was being manipulated by the Ascians, as far as the player is concerned they are not tempered because they can't be - they have the Echo after all and it's a major plot point of the game that the player is completely immune to Primal influence (ala tempering), making them uniquely suited to bending the Primals to their own will (or at least a portion of their power).

Tristan unfortunately was so consumed by revenge it virtually destroyed him (especially wielding the very powers he hated so much), but again it was unclear whether or not he was tempered himself.