So all our characters would have some knowledge of magic? If my pikeman knows some magic, he'll probably know the least amongst everyone in the group. He's a pikeman, but he's also a town guard and therefore a volunteer with a domestic occupation that he's equally capable in. So the magic he knew will probably have a civilian/domestic origin and use, just that it would have to be bent towards use in the field. I'm thinking he could have a relative who was a healer and he/she'd taught him a bit of it. Either that, or I'm thinking he could be a shopkeeper, and peddles trinkets amongst other things like tools and wares, and some of those trinkets could be protective charms, which would make him an enchanter, but by no means a powerful or even adept one.