Ah now I get what you mean. Okay so you have spring_soil_auto and spring_dirthpath_auto in the autotile folder because they are "flipped" versions from spring_grass_dirt and spring_grass_soil.
So when you have a big green area you can have a second layer and draw in soil and dirt directly, as in pathing it rather than map out everything in one go. I'm also not a dev, but I found that easier when setting up test levels to try my auto tiles.
Hope that makes sense!