I could be the most experienced, wise enlisted person in the world and a 2nd louie would outrank me and be able to give me orders. If he wasn't a complete prick, he/she would listen when I said "If you do that, we'll all die." If he/she was a complete prick, he/she would say, "I gave you an order. Make it so."

Here's the hard part: if he/she were only a partial prick, you might end up with, "Well gosh, I don't know... What do you think I should do, sergeant?" And everybody would get killed waiting for the incomplete prick to make a decision.