Okay, Dowman Sayman is known for his mind screw, but it seens that it did all happen because she said the combat happened while she was at school, so she couldn't have destroyed her manga manuscript in her sleep and just imagined it or anything like that, not to mention that Dowman created things weirder than living objects, so I don't see why it's so hard to believe that it all really happened.
As for the supposed pregnancy, the sweat was because she had to run a marathon for phys ed, as for what the stationary said, they said that they will leave the outcome of the war to Asami and that to protect what is born between them they hope a new leader will guide them, a leader probably chosen by Asami, now, I guess this point flew by everyone heads, but she's trying to be a mangaka, they're drawing tools, what is born between them are mangas, they didn't try to mean that a human-stationary hybrid would be born from them raping Asami in her sleep, but that the manga manuscripts she makes that they keep destroying in their war is what is born between them.
In the end her choice was to destroy both factions and to use a laptop instead, the reason she puts her hand in her belly is because she's hungry from not having enough money for food from expending a lot of it either to buy the laptop or the Clip Studio program and drawing tools for her laptop, maybe both, also, she's not using a tablet, what she's using is a drawing mousepad, she says she wants a LCD tablet exactly because Clip Studio is hard to learn to use and drawing in a tablet would be easier than drawing in her laptop.
As for what the story might mean, I don't think it has anything to do with war at all, because not only she was a neutral observer to who they asked permission to use their newly created weapons, but in the end they left the outcome of the war to her hands, which ended with both factions destroyed, of course it could represent Mutually Assured Destruction and how someone else would take their place, maybe Asami could also represent God, but if anything I believe this could an allegory about how a mangaka life is hard, the writing and erasing faction destroying her manuscript could represent how a mangaka sometimes need to give up a manuscript and start from scratch, her stationery wrecked and scattered around could represent how they're used a lot, their new weapons that she denied the use could represent things the mangaka thought they could try but didn't use in the end, Asami getting home tired from the marathon she had at phys ed could represent how some mangakas sometimes have other responsibilities and jobs that takes most of their time and energy and that being a mangaka is something they do on the sides in their free time and might even pull all-nighters just to do it because they love it and can't always have it as their main souce of income or priority, Asami loving her stationary from the bottom of her heart could represent how some mangakas need to take a lot care when using their tools to use them for a long time because they can't always buy new ones, them leaving the outcome of the war to Asami could represent how in the end it's not the tools but the mangaka that matters and who decides how the manga will end up, Asami waking up and finding that the stationary stopped walking around, talking and fighting could represent how eventually their tools will stop working and the mangaka need throw them away to buy new ones, which will make a hole in their wallet and they'll have to cut some expenses, like food, the end of the story basically shows that to be a mangaka you need to endure being hungry, tired, without much money and on top of all that deal with deadlines, in other words this story tell us how being a mangaka is suffering.
Now I kind of wonder why I'm the only one who got this conclusion, if it was because you guys expected something weirder from Dowman Sayman, if no one paid attention to the story, or if I'm the one strange here because I thought too much about it or because of my conclusion, maybe both...
tl;dr: I need a life.
