Thank you for taking the time and effort to create and post this video. It's always great to see these clear examples that are the result of corresponding management..
Excellent demonstration and explanation Chuck! Sheep seem to be well suited for this type of orchard situation. I graze goats, and was imagining them climbing all over the trees. Perhaps with a taller canopy, goats could be of similar value for grazing the forage cover. Question, how are these aisles going to be managed prior to harvest? (you indicated that they wanted them bare for gathering nuts.
The covers are mowed tight in the middles so the nuts can be laid down. There is a picture in this video that shows the nuts windrowed. Because it is dry in the summer, the mowing completely terminates the covers. The tree rows still have vegetation because the nuts are caught or harvested off ground and then laid down. Goats will likely get at the lower limbs, or likely will do so. I would first suggest a small paddock and watch them closely.