First, did I blast Miho
et al, or did I blast the scriptwriter forcing them into such actions or assigning them the hit rates shown onscreen.
Anyway, I don't think I put a lot of emphasis on them, or any other character, acting to the standard of trained professionals. I
do remember demanding they act to the standard they had already achieved. If the story has already decided they can shoot and hit to a certain distance, I expect to see that retained, not dumped because the author decided the story he wanted to tell here and now needed them to keep missing. At the very least, the author can add reasons for missing. When the tanks are literally sitting across the street from each other, filling the scopes and not moving, he is making it as hard as possible for me to swallow the scene.
Spoiler for Theme vs Characterization:
As for Theme vs Characterization, I think there is a cultural divide. My sense is that Westerners tend to emphasize Theme, and Easterners emphasize Characterization. When I see Eastern reviews, I don't see much emphasis on Theme, and more on how characters are "moulded" correctly or incorrectly. You can really see this in the spat a year or two ago in Pokemon anime. Westerners tend to be more accepting that character called Goh because he's "new" and has some interesting themes. Easterners were more concerned about how the clumsy attempts to play out the "themes" meant that old-standing rules and standards (worldbuilding and characterization) had holes punched in them and had unrealistic visions of Goh being taken out by a car. By the end of it, so much damage was done that we now have a new Pokemon anime, with new characters and basically a new worldview.
From where I'm sitting, I find myself sympathizing a lot more with the Easterners. Before we even discuss which is more important in the end, most of the time there's no essential conflict. It's just sloppy writing or planning, or the writer wanting to have his cake and eat it too. If your "theme" needs the weaker-shooting team to win, just have them improve their shooting. We hadn't seen most of them in months, which is a long time to bring a weak area to at least adequacy especially since yes they are HS students without a huge base number of hours.
Sometimes, it's just a matter of not adding legs when drawing a snake. For example, was there really a need to add that last rush bit to that Shirobako movie? Or did it just have the effect of weakening the messages it's trying to deliver by violating its own stated rules.
To my mind, Theme Priority often ends up being an excuse for sloppy storywriting, both for the storywriter and the apologists in the audience.
If all authors want to write their themes, then we educate them that characterization is the priority - that way they will handle the basics as well as the theme, and the story will come out smelling like roses. Also, even if they don't quite hit the theme if they have made pleasant & likable characters, at least the product will probably be worth a casual watch or read.