Very cool to see he's using prickly pear cactus. I'm currently working on a project for regreening arid regions in California using prickly pear on degraded water-restricted former agricultural fields. The prickly pear really is optimally suited for regenerating desert landscapes because they are one of nature's great survivors of extreme conditions. Furthermore, they can produce impressive biomass yields which helps drive significant amounts of carbon underground which helps to structure the soil and feed the soil microbiome / establish mycorrhizal networks for other plants to be subsidized with. Plus all parts of the prickly pear cactus are edible, the fruits are delicious (great at reducing LDL cholesterol too). They are prickly as a mfer tho, my goodness, watch your hands! Plus in the America's they are native and so have natural biological controls in these ecosystems that help prevent unwanted runaway growth. Lots to love about prickly pear!
I hate to be negative, I do, but Shaun Overton is a fool. He's wasting an enormous amount of money, energy, and time to achieve approximately nothing when he could do so much more if he expended those resources on a non-idiotic project. It's his time and money to waste, but it hurts to see it when he could really do a lot of good with it instead. His heart's in the right place.
I'm not familiar enough with the topic to know if you're correct or not, but I don't watch his channel to see his project work out, seeing him learn small things along the way and share that journey but also him connecting with himself and the community around his land in unique ways through his project is intriguing and hopeful. A mad dream pushed forward by a mad man, which may not come to fruition, but it's a whole lot more entertaining than watching people take on small projects that are guaranteed to succeed.