So to my understanding we can’t do this achievement unless we revert back an old version? Or do i just keeo placing new thralls on the work bench until it does it?
I can’t test it (because I completed it years ago), but I have seen a few people report that it is supposedly possible. From loose memory, it may have required something like placing the (crafter) thrall on guard close to the bench, then moving them from there to the green silhouette. If that doesn’t work, you could try other combinations of similar ideas. But there’s no guarantee it will work - as I said, I’ve seen a lot of reports on this one since Living Settlements was added, mostly negative.
The other alternative, if you really want to do it, would be to reinstall a version of the game from before Living Settlements was added. That might work, if older versions are able to trigger achievements (I have no idea if they can). Apparently Steam has some sort of guide for installing older versions. It seems like a lot of work for no major purpose to me, but if you really want the achievement, I hope you are able to get it 
.
AFAIK this one was fixed with CEE.
If Dan’s suggestions have worked or not, please come back and tag me.
If this is not fixed I will add it to the Bugs & Issues list.
It did not work
Ok I bookmarked so I can add it to the list.
So did I lol
Great minds think alike!