I was trying to equip Astarion with a dagger or short-sword in his off-hand and it wasn't being allowed. Is dual-wielding being limited to certain classes?
What weapon was in his main hand? Without the Dual-Wielder Feat, you can only dual-wield if
both weapons are light (e.g., dagger, handaxe, short sword, scimitar).
All classes can dual-wield.