Another Option
The idea of rankers being separated into classes like mages, paladin, ranger and so on did not come into existence because it was discovered that people could only engage in a specific way of using mana, no.
The idea came about because it was discovered that many people tended to be really good at using mana in a specific way and also because of how vast the field of magic was.
There were so many fields of magic that one could learn from and depending on how fast one progressed as a ranker, they had lengthened but limited lifespans they could use to further study.
Of the several warrior category classes that existed, the paladin, fighter, battle mage, warlock and knight were the most popular and strongest of them, and of these classes, Hannah fell into a complicated case.