Officer of the military ≠ officer in the military. Looping back to the point other commenters have made about civilian leadership over the military, the relevant section of the 14th Amendment establishes the existence of civilian offices under the US. The court finding also refers to POTUS as “Chief Executive Officer of the Executive Branch”. In each hypothetical scenario of the Commander in Chief being categorized as a civilian office or instead being categorized as a military office, it is covered by the critical word “or” in “hold any office, civil or military, under the United States…”. Ultimately, the role of Commander in Chief is an “office, civilian or military, under the United States”, and to “have engaged in insurrection” while in this office of the US would disqualify a person from holding this office again (except the court decided otherwise 🙄).