I'm imagining something along the order of wide-spaced modern orchards, which have tree spacing of ~20-40ft. I wouldn't exactly call those "mild shade". I just

I'm imagining something along the order of wide-spaced modern orchards, which have tree spacing of ~20-40ft. I wouldn't exactly call those "mild shade". I just don't see any benefits beyond companion planting with a groundcover crop like cucurbits, which would be far easier to mechanize.