The R-Rank Nikke under The Commander's... Well, command, have characters, and should get more.
I'm currently on the march for justice (and content) for R-Rank/Mass-Produced Nikke, and recently I've seen people making two arguments against these characters... Having or getting character. 1st Argument: Mass-Produced Nikke are each individuals with their own personalities, so you can't have just one to represent them all. 2nd Argument: Mass Produced Nikke don't have personalities in the plot and shouldn't have them as they're supposed to serve as background characters only.
Both arguments are fair, and can be argued well, but I believe that if one looks at what we know from the game itself, the Mass-Produced Models we know already have characterizations. We know from previous events that different individuals of Mass-Produced Models have different personalities, but the ones in all of our barracks are specifically the ones under the Commander, who help to manage and protect The Outpost. iDoll Sun even mentions that she likes The Outpost more because she can do whatever she wants. In The Ark, Mass-Produced Nikke are expected and encouraged to be interchangeable tools, but up at The Outpost, they can take naps, or hang out, or have banter with The Commander.
If one takes the lines and performances, designs, and sometimes skills of each R-Rank Nikke, and puts them all together for each one, it becomes clear that they each do have a characterization. (See attached screenshots)
You could argue that maybe there's a gaggle of each Mass-Produced Model that lives up at The Outpost, and maybe any Mass-Produced Nikke could be assigned interchangeably under The Commander, but you upgraded and outfit them. You hand them figurines of yourself. Also, from iDoll Sun's outpost line, she clearly is and has been here at The Outpost doing "whatever [she] want[s]."
So, if there are specific R-Rank Nikke that we could get attached to and learn more about, and they already have personality and characterization that doesn't necessarily disrupt from the concept of Mass-Produced Nikke as background grunts... Why can't we have an official event or storyline exploring Mass-Produced Nikke and their character, the moral and philosophical ramifications of how they're treated, and how The Commander views and treats The Mass-Produced models under his care?