Plot and the MC's character is all over the place. It's rushing through a lot of details with extremely poor introductions and worldbuilding (even for a trash fantasy manga, which is saying quite a lot), and the MC doesn't feel consistent when he's both oblivious but not and intelligent but not.
Wait, what? They suddenly decide the slave merchant was being dishonest, the price is somehow higher than he said, and he never intended to let the girl go despite letting her stay the night with them and, to the merchant's knowledge, having her potentially lose a big selling point? Wtf? What...
The source of the wood doesn't entirely matter, a tree farm appearing on their land at all is enough to sour relations and cause wars. If the trees could at all be traced to Capua, it would harm Capua's relations with the wood suppliers (which is not what you want in a nation still recovering...
It would become obvious that they stole the seeds without permission when they stop buying wood or suddenly have a big plot of land with lots of trees growing on it, and that would harm relations and absolutely become something held against them. It would also give a reason for war (even if it...
Princess Margarita calling herself plain while being the most attractive woman in the twin kingdoms, lol. Definitely my favorite character in the Twin Kingdoms, but then we don't get a lot with most characters.
Never a fan of the 'our fists will make us brothers' trope. Not a fan of the 'I will only serve someone who can beat me up' trope either. Not a fan of Chaos either. The witch had the right idea.