That makes enough sense for me. I'm familiar with layers from Photoshop, and I had tried another run at making the same river channel here:

https://cdn.discordapp.com/attachments/169758353663197185/365322347496079360/unknown.png

I found it was easier to paint the layers first and then the area I wanted to alter as a straight line, then terraform it and smooth out the edges. It turned out much better than my initial try.

For now, I'll probably stick with just sand and grass, then dabble with water when I get to that part before I dabble with the multiple layers as I would prefer to watch it or see it done myself before I open that can of worms.

Thanks again for the previous posts!