Str: Fighter. Archetypes are Weaponsmaster, Paladin, Battlerager
Dex: Rogue. Archetypes are Bard, Ninja, Thief
Con: Shaman. Archetypes are Druid [nature magic & totems], Ranger [less magic, more fighting], Shapechanger [no magic, some kind of strain or dice pool].
Int: Wizard. Archetypes are Evoker, Illusionist, Necromancer
Wis: Adept. Archetypes are Cloud Stalker [mobility, sneak attack], Elementalist [focused on one element], Pugilist [emphasis on melee combat]
Cha: Cleric. Archetypes are Battle, Healer, Inquisitor [skill/info based]. Clerics are supposed to be leaders, orators, and counselors. Charisma makes a reasonable amount of sense for a casting stat.
Intentionally mapped to Final Fantasy 1's Fighter, Thief, Red Mage, Black Mage, Black Belt, White Mage.