I remember those from my winters in West Texas. Always thought that only a pervert would plant them on purpose.
Those tiny blond stickers that must be pulled out of the skin with pliers is what puts me off.
My son wanted the cactus. Driving it home, he noticed a black widow spider on it. We pulled over and released the arachnid out of the car. And it has just taken off ever since we planted it.
But you don't like the natural fence idea? Growing some plants is a tough business in TX. I have fruit trees and such, but other things are hit and miss. These cacti just love it here. So I keep going with what works. And that way, later on when I get sheep, they will be penned in all round by cactus. I don't think sheep will eat them. Goats will eat anything, though. There's a goat farm down the road. I should ask.