This tier list includes 4 stars and 5 stars.
For ascension & talent material farming guides, see links below.
Quick note: The Traveler uses all sorts of enemy drops as Talent ascension material. For Talent books, the traveler uses all books from the respective region. (i.e. Freedom, Resistance, and Ballad for Anemo)
Kazuha
Puzzles, Secrets, and Hidden Chests in Dragonspine
Shenhe
Puzzles, Secrets, and Hidden Chests in Liyue
Hu Tao
Mimi
ATK% VS Physical/Elemental DMG% in Genshin