Taking advice, I devised symbols for each class. Following are the twenty classes and their symbols. The sex of the people in each symbol is the sex of the individual bearing the symbol. The people are nude, but as this is a silhouette nothing is shown. These are all metaphors. Go ahead and try to interpret them yourself. Some should be easy, others should be difficult. It might be interesting to try and interpret it, but I must warn you that some of this imagery is DARK.
Soldier: A dead child being eaten by a dog, lying inside a black, heart-shaped box held by an iron hand.
Warrior: A child bearing a sword, facing a threshold with a large horned shadow coming through it.
Martial artist: A child, hand up, with a velvet-gloved, iron hand guiding their wrist.
Guardian Sentinel: A child clutching a heart-shaped box to their chest. Several adults are visible through the box's lid.
EDIT: I retconned this to avoid confusion between the guardian class and guardian deities.
Lawman/Lawwoman: A dead child being beaten with an iron fist.
Scout: A child, in a tree, with a looking glass.
Bard: A child with a lute, writing with a quill upon parchment.
Ranger: A child, arm outstretched and a bird landing upon it.
Rogue: A child hiding behind a counter holding a knife and a loaf of bread, before a threshold with a large horned shadow standing in it.
Mystic: A blind child holding a hand of cards: The World, The Fool, The Tower, The Lovers and The Devil.
Savant: A child sitting on a chair, reading a book by candlelight.
Artisan: A child sitting at a desk, sketching.
Noble: A child wearing a black coat, with a red right hand clutching green paper to their abdomen, fingers in their coat.
Worker: A child, holding a pickaxe, being struck with a whip.
Shaman: A child sitting against a tree watching a dog, while the dog watches an owl and the owl watches the child.
Priest/Priestess: A pile of burning books and an iron fist beating a dead child with a rod.
Physician: A headless child kneeling next to a beheaded adult, trying to put the adult's head back on.
Wizard/Witch: A child wearing goggles, holding a vial and a quill.
Sorcerer/Sorceress: A child, arms outstretched like wings, flying through the sky.
Mage: A child with a looking glass, sitting on the crescent moon.
If nobody can figure this out in three days, I'll explain the lot of them. Don't be afraid to spitball.