Shaman Archetype (Spirit Warden) is missing some key features
When choosing the spirit warden archetype as a shaman, you can't choose a starting spirit. Even if the "Unnatural Mien" class feature replaces the "spirit magic" class feature, meaning the spells you usually get from your first spirit are replaced with a fixed list of spell from the archetype, the "Spirit" class feature is not replaced. You should still have a spirit at 1st level, your spirit animal will still gain the effects from that spirit, you still gain the list of hexes from that spirit to choose from when you gain hexes, and you still gain the spirit ability, greater spirit ability, true spirit ability and manifestation from that spirit.
The fact that no spirit is chosen at level 1 removes many of the ability this archetype is supposed to have.