A review of Cannon’s decision by Cato: https://www.cato.org/commentary/analyzing-judge-cannons-opinion-was-jack-smith-legally-appointed
Personally, were I before the Supreme Court, I would argue for a basic assumption that should underlie any legal analysis: The Framers and Congress aren’t stupid. If there’s an interpretation for a contradiction between some portion of the laws and another interpretation that suffers no such conflict, then the second interpretation is correct. It’s ridiculous, for example, to say that the Constitution includes impeachment by Congress, but then say that impeachment ruins the separation of powers or goes against the democratic process that the Framers intended. Clearly, they had no such fear or they wouldn’t have written it that way. We’re just inventing problems for the sake of inventing problems.
Likewise, if Congress wrote a law allowing a cabinet member to appoint a particular position then, whether they called that position an “inferior officer”, explicitly, or not, there’s no reason to assume that they had any other intention. They’ve described a process that aligns with the appointments clause for how to generate an inferior officer. Why presume that they had some other non-Constitutional intention, when there’s nothing about the position that’s been describes that departs from the parameters of an inferior officer?