So I didn't make my gnomes murderous fungus people, but I did draw on the ork ability to make their technology work because they believe it works. Gnomes are describes as tinkerers who build fantastical technology, but this somehow never impacts the world's technological level. I decided that in my world, large numbers of gnomes living together can make their technology work just by nature of being there. Take a gnome invention away from gnomes and it will suddenly malfunction, explode, or just be a hunk of scrap. This also scales with the number of gnomes present. A small village could create some interesting gizmos like what you get from the rock gnome pc stats. Meanwhile my world's biggest gnome city is a bizarre place made of towers where buildings were just plopped on top of each other with no thought for stability or safety and remain standing despite being completely structurally unsound. They are connected by haphazard bridges and cable cars and the city is alive with the sound of clockwork robots and the flapping of ornithopters. Its a place of nonsense and even though its part of a larger empire, the empire lets it be pretty much autonomous because they're afraid that if they step in, the whole place might collapse or explode. Artificers in my world were the result of an attempt to make gnome tech that everyone can use and that wont explode if there aren't enough gnomes around