Final answer:
The repeated use of the phrase "some scholars" and the use of the phrase "recent studies" suggest that historical interpretations about Aztec tribute and the main purpose of Aztec wars are subject to change as new information is uncovered.
Step-by-step explanation:
The repeated use of the phrase "some scholars" suggests that there is not a unanimous agreement among historians about the categories of Aztec tribute and the main purpose of Aztec wars. Different scholars may have different interpretations and theories based on the available evidence. Similarly, the use of the phrase "recent studies" suggests that new information is being uncovered, which could potentially challenge existing interpretations and lead to new understandings of these topics.