The Bannor should not have anything that makes them inclined towards the Arcane.
The Bannor more than any other race still sees Magic how it was seen by most in the Age of Magic: as a perversion of natural law which is an intrinsically evil and leads its practitioners into corruption and the worship of Ceridwen. They were then the people of Bhall, famed holy warriors who sought out witches and purged the land of their evil with the sacred flame. Although they now serve Junil, an affinity for their old precept remains and drives them to continue their witch hunts, although since Bhall's fall witch hunts have more often then not been directed against the innocent. Much of the world had their opinion of magic changed when Kylorin reemerged to teach the Amurites to use it for good and then himself went on to end the Tyranny of Mulcarn, but the Bannor were not present in Erebus at that time. They probably were allied with Kylorin against his empire, but I don't think they ever really trusted him. Also, I don't believe that Kylorin had begun training under Nantosuelta yet, so he may have personally avoided magic during their alliance and seen it as the instrument Ceridwen had used to turn him into a monster more than as a tool he could use to set things right again.
I've seriously considered making the Bannor unable to get Archmages. Archmages, but the definition given by Malchiavic, must have such strength of will that they think past any laws or notions of good and evil that might stand in their way. This by no means requires them to be evil (in fact wanton acts of cruelty would generally be counter productive, and many archmages prefer to think of this as focusing on a higher good) but it requires them to trade their idealism for a pragmatism that goodly nations still see as a sign of corruption. An archmage cannot let himself feel regret or doubts over murdering an innocent man if that death serves a greater purpose, but the Code of Junil would not let a mere mortal make such a decision.
.
