I try to get pigs with tamworth in them, they are the rootin’ist pigs I’ve seen.
I run my pigs in an 8x16’ cage and move it every day. They strip it bare and it is the best looking grass when it comes back of anything on the field. It comes back faster than I would need to come back around again. They do have areas they cause depressions.
When you move them they run to the new grass to start eating
I do feed non gmo also and have a lot of Johnson grass which has rhyzomes and they seem to love it. But like I said, the grass comes back great which will be the same for your garden.
Edit...my last set I got at 80lbs and they were butchered at 285 after 3.5 months. Most delicious I’ve ever raised (tamworth/Berkshire mix)