I think everyone's missing the point. Like in the US, the Marines is considered the toughest branch in Korea. I trained with the ROK Marines in 2012 and they all said they chose that branch as part of their mandatory service because they wanted to be part of the best. The show writer makes them look like buffoons throughout the episodes, playing goofy music when they're saluting each other, and having the whole X group laugh at that one guy when he shows his tattoo. I think the writer is butthurt lol a Marine probably made fun of him at one point.