And what's interesting is that the roots of short and mid height vegetation join together, creating a dense mat of roots and fibers, that contain a surprising amount of mostuire. When you combine that with spongy soils, buried wood, and shade they provide localized cycles of fluids and humidity. Overall it makes for much more resilient and productive food systems. Though you have to pay more attention to what you are doing.

If you plant one by one, neatly spaced apart, you won't have this type of nutrient cycling and moisture uptake.

In this context, what's a very dry area? I get 11-12" of rain annually; generally none May through October.