For most vertebrates like humans the majority of their neurons are in a little thing in the back of their brain called the cerebellum that is responsible for motor functions, not consciousness. Bringing up a creature that doesn't have a brain in the same sense that a monkey or a pig does in the case of a nematode begs the question of how many of those neurons are dedicated to what. Your estimates could be a lowball or totally blown out of proportion. Assuming there's a significant chance that nematodes or insects are sentient then it should be taken very seriously. There are all kinds of different types of nematodes that remain unstudied. How many of them are going to be impacted by agriculture? You don't even seem to be clearly proposing that agricultural expansion is the best way to improve their well-being or reduce their suffering, just a way.
For most vertebrates like humans the majority of their neurons are in a little thing in the back of their brain called the cerebellum that is responsible for motor functions, not consciousness. Bringing up a creature that doesn't have a brain in the same sense that a monkey or a pig does in the case of a nematode begs the question of how many of those neurons are dedicated to what. Your estimates could be a lowball or totally blown out of proportion. Assuming there's a significant chance that nematodes or insects are sentient then it should be taken very seriously. There are all kinds of different types of nematodes that remain unstudied. How many of them are going to be impacted by agriculture? You don't even seem to be clearly proposing that agricultural expansion is the best way to improve their well-being or reduce their suffering, just a way.