Contradiction with Numbers 3:45
This verse does not directly contradict Numbers 3:35 but instead discusses the exchange of the firstborns with the Levites, providing a broader context about the role of the Levites, which complements rather than opposes the hierarchical setting among Levites mentioned in Numbers 3:35.
Numbers 3:45: Take the Levites instead of all the firstborn among the children of Israel, and the cattle of the Levites instead of their cattle; and the Levites shall be mine: I [am] the LORD.