I've known several offices and high-ranked enlisted military members. This is what I was told:

Yes, the most junior of commissioned officers fresh out of academy technically outranks the most senior non-commissioned officer that's been there for 20 years. Also, you can bet that that junior officer will get a very thorough chewing out if s/he ever disrespects the experience, commitment, and knowledge that NCO rank represents.

I was in the US Navy, and had well more than 6 months in before they put me in charge of anyone.

Until that officer is in the jungle. All the sudden the Sergeant runs things real fast.