These 3 new PRCs, Priest, Mage and Scout can't overlap easily as they need different base classes.
Priest : Cleric/FS, Druid/Shaman and level 3 divine spells
Mage : Wizard/Sorc/Bard and level 3 arcane spells
Scout : Ranger/Paladin and level 1 divine spells
Harper Agent is unchanged so you can go Harper Agent/Harper Scout if you want, however the synergies should be rather small (should be counter productive even, power wise).