Grasses love nitrogen and rich soil, especially the heavier grains.
I’d treat the sorghum about like sweet corn, for soil preference and spacing.
Quinoa grows like amaranth ?
Could almost broadcast, lightly, and let it take over a portion.
I did harvestcamaranth seed in my wild-foods-obsession-as-a-teenager years.
Lot of work for a quart.
But quite nutritious.