Yes, I am. The Air Force should be part of the Army. A Space Force fights extra-planetary operations. They have a distinct battlefield. You can occupy a location in space continuously (in theory if not reality) using a space station. You can have long-term fleet operations. Thus, they are the equivalent of a navy or army in space.
The atmosphere around a planet cannot be so occupied by some reasonable means. You hold ground or you control bodies of water. You can do either on a sustained basis. All air forces--whoever controls them--do is add a third dimension to existing warfare.
See Chapter 17
Or, see chapter 11 Non strategies
xii, 283 p. ; 25 cm
archive.org
Douhet, Mitchell, and Seversky are picked apart with ease.
You need a separate Army and Navy. The navy needs marines and an air force, while the army needs an air force. You can have a separate space force if you want.
That works with a small military, but a large one needs to be divided between land and sea warfare to make sure each is focused on their aspect of warfare.