Indeed. I cannot help but wonder how all of these understandings came about.
I do think it demonstrates why 'mix and match' can cause confusion.
I can give witness to that. Here in Brazil, specifically, there are many Kardecist Spiritists that sell a very distorted understanding of Karma, mainly because they insist on presenting their doctrine as an "evolution" and true successor of all others, explicitly included Christianity.
Their understanding of Karma is
very flawed indeed (as is their whole doctrine, but that is matter for another thread), apparently because their dogma insists on claiming:
1. That there is a God
2. That he made Existence so that everyone is destined (even doomed) to grow in "spiritual evolution" indefinitely, without ever "regressing".
3. All other faiths are incomplete or mishappen versions of Kardecist Spiritism, which was revealed to them by "Superior Spirits" in the 19th century.
It is a mess. And a very dangerous doctrine.