I think that is wise advice for gardens with much better soil than mine.
I have a lot to learn about gardening beyond the growing of good roses, but I think the most important thing I've learned over the years is to observe how your soil works with your plants.
Gardening in glacier slurry is what I consider to be an adventure. The water doesn't always go where you put it ...

It can go down or it can flow sideways, depending upon the density of the rock below the surface. That's why it is best to place anything that might decompose on top of the the soil.
Smiles,
Lyn