None of them called him the "ship's omega." It wasn't... really like that. A lot of ships had omega crewmates whose station was defined by their secondary sex, or at the least who joined up knowing what their job was among a shipful of pirates out to sea for weeks at a time. Zoro was not that. He wasn't a friend with benefits or a glorified servant or even one of the so-called Crewman Os who had their own jobs and stations but lay down and made their bodies available when a crewmate needed it. He was just... Zoro.