confusion about some of Sepp's techniques

I grow in deep beds with good success, I mulch with 3 - 4'' each spring and have little trouble with weeds ... my confusion arrises when I watch some of the videos by Sepp etc and see what appears to be swales, but you can see them running down hill and not around the hill? I know he builds deepbeds too but they appear to be full of wild flowers etc with some veggies? am I correct in thinking he does not mulch? I'm hoping to move o France in a year or two and it will be much dryer than where I am, I planned on using loads of mulch, perhaps the difference is that it is quite wet where Sepp farms?
Can someone please try and explain what is going on or am I missing the point somewhere?
TIA