Hi. Thank you for your message. As for Officer Arnette, (Arnette is his last name, we still don't know his first name, unlike Officer Mike who's called by his first name.) yeah, I see what you mean. There's a portion where the the other inmates and the narration calls him Arnette but MC still calls him grumpy but switches to "Arnette" in a few lines. Although the intention was to suggest that he uses them interchangeable as a part of a habit of only recently learning his last name and was used to Grumpy, but I can understand its a bit jarring and I'll re-read that part later.
As for your second point, yes, Officer Arnette is only available as a choice to hang out with if you meet a certain condition, unlike the three other inmates who are there no matter what. There's an internal point system that tracks how much interest the player has with a particular character. With Arnette, if you reach that point where you fantasized about him, you can pretty much unlock most of his scenes in this update. (I'll soon make an in-game walkthrough option that gives tips on what each choice does.)
As for the last part during lunch. Yeah, haha. It does seem like they're all grouped to one side. I did actually place more inmates there than the other side of the room. There were inmates behind Carl but at that specific angle from Carl towards the table where Eric sits, there weren't. I guess the shots I took emphasized how empty that part is. I'll keep this in mind in future scenes.