I just read _Made Things_, by Adrian Tchaikovsky. Not like Discworld, not funny, but very good. It has been described as faintly similar to The Borrowers, but the point of similarity is small beings in a big dangerous world. Tone is faintly similar to Truckers/ Diggers / Wings but again, not the same. Homunculi of various types, on their own, need to get more magic to create more of their kind.