Picards route to command... His Captain died while the ship was in a fire fight, the rest of the crew panicked, but he stood up, threw a corpse out of his seat which god said he deserved, and saved the day. Starfleet was so impressed that they let him keep the ship.
Picard was 27 years old.
From Memory Alpha about Operations officers...
On board starships, the role of the operations officer evolved from older 23rd century positions, such as involving some functions of the helmsman (although the bulk of duties that the helmsman and navigator were traditionally assigned to were filled by the flight controller). As well as manning the ops station (as such, overseeing internal systems control, communications and sensor system usages), ops personnel also coordinated the scheduling of resources, hardware and system usage for an entire starship, outpost or space station.
I repeat, Kim did the job of a quartermaster even if that wasn't his title.
Of course, "personal" items for crew are handled by replicators, so it's not like he's counting blankets, and making sure that crew doesn't get new boots until the old ones are worn out, although he would have been the bean counter keeping track of everyones replicator rationing and if he wasn't so square he might have considered cooking the books.