You are wrong. Enlisted and Noncoms do have the potus clause in oath. Officers take a different oath. See the link below for the officers oath.
https://history.army.mil/html/faq/oaths.html
“I, _____, do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; and that I will obey the orders of the President of the United States and the orders of the officers appointed over me, according to regulations and the Uniform Code of Military Justice. So help me God.”
(Title 10, US Code; Act of 5 May 1960 replacing the wording first adopted in 1789, with amendment effective 5 October 1962).
I never once swore an oath to the President, as I was a commissioned Officer in the US Navy.
You are wrong. Please do a bit more research.