Green caterpillar eating my greens

I have a large raised bed devoted to greens. Right now something has been eating my PAC Choy and has moved on to my broccoli raab. It appears to be a small green caterpillar which you see on the broccoli in the pic I posted if you look carefully. Anyone know specially what these are and any ideas on what I can plant along side to prevent further damage? I have sage rosemary and Tyne already planted but they don't appear to be helping. Would dill be a good idea?

its the white butterfly you see dancing around. I generally hand pick. I think marigold is used to deter but frankly I try not growing until after mating season

Yes, the cabbage butterfly lays its eggs on the underside of leaves. Sometimes you can find the eggs and remove them, other times you remove the little caterpillars. I've always pretty much ignored them, they haven't wiped me out. Yellow jackets eat caterpillars, you should know. Birds as well, but most people know that.

One other thing as a new gardener myself I would suggest a soil test. Recently watched a video explaining that insects that are in the larvae stage cannot digest complete proteins. It would suggest perhaps some deficiency in the soil or plant itself. How he described it is that insects are natures way of removing less than optimal plants from the gene pool. More complex than that but I have limited understanding of all this. But it at a high level makes sense. So it could be a soil issue rather than a pest problem.