It doesn’t follow at all. In fact, a president’s closest advisors usually are NOT cabinet officers. For instance, Flynn might be more likely to be selected as National Security Advisor (who serves in the White House not the Pentagon) and Christie might be more likely to be in the White House as either Chief of Staff or as a “Senior Advisor” type behind the scenes.
I say “might” because we just don’t know. From the fact that Flynn and Christie were included we can infer that they are likely to receive some key appointment in a Trump admin. but not necessarily Defense or State.
Thanks. Sounds reasonable.