Horses allow the shaman to fly, take a trip. Smiths are second only to shamans in terms of importance - so shamans can not swallow the souls of smiths. Smiths have an important function and their own rites. They have a closed society as well and the secrecy leads others to fear them and their powers over metal and fire. Shamans have the cool power of being able to shoot fire from their body, even if they don't eat beans.
Mystical heat is required to resist the cold, etc.
Sort of a cheap shamanistic power. Like sorcerers, etc., shamans can fly, in Siberia, Alaska, and North America. This is part of bird-worship, including the use of bird costumes. Even Christian saints can fly, like shamans. Many people outside shamans believe in the bridge mythology surrounding the journey to the underworld.