When I studied alchemy I was so confused as to why avatar used the western 4 element version instead of the 5 element Wuxing then I realized the Japanese / Shinto also often use a 4 element version because apparently a lot of it goes back to a mutual origin in Buddhism. (Well sort of 4, they both also often include a 5th spiritual aether element and also it turns out the wuxing is often just used to describe transitions vs the 8 trigrams are more analagous to the elements but also they don't fit neatly into the 4 aaaand... it turns out spiritually is complicated and highly culturally contextually, who knew?)