I had a suspicion before, but now confirmed it: I must have made a mistake when first generating the kingdom world. It is NOT large biomes but just normal. I have rendered a map of how it would look like if it was large biomes and while the center looks quite similar, all the rest from there is quite different. Take a look here. It is essentially zooming the whole map in by a factor 4. Given the fact that large biomes are that large… I guess this is a good thing.