Nitpick: Why did the Valiant have an acting Chief Petty Officer? A CPO is a non-commissioned officer. A non-com is an officer who is given a position of authority by a commissioned officer, like Chief O'Brien. None of the other Red Squad cadets had finished their Academy training, but all had ranks of commissioned officers. Collins was a Starfleet cadet as well, and therefore shouldn't be the only one with a non-com rank.