If you were to put magic into redwall... the only magic I can see being in this universe is divination magic or even illusion in some cases taking out the spells that deal damage as manifested abilities. Maybe some spells could be reflavored to be morale bonuses? There is a lot of morale boosting type warlord like events seen in the books.
edit. In fact if hit points were relfavored to be more about morale of your character rather than strictly your ability to fight. Healing spells can be reflavored as well.