I knew you were going to mention Landrace Exchange. So I’m not really sure how it all works either, but what I can tell you is this.
I ordered two packs of seeds from Landracemafia - Hindu Kush from Andarab Villiage, and Tashkurghan aka Kholm. Out of 24 seeds, I was able to get 4 of them to germinate. At the same time, using the same methods, I had 35 out of 36 domesticated seeds germ. When I contacted Landracemafia about this I was told; I should not have used paper towels - landrace seeds like to be sown directly into soil, all his seeds are guaranteed, but he’s out of those b/c they were sourced from Baba78 or whatever his handle is, he would be getting more, and I never heard anything back…
Maybe I just suck, but it was enough for me to give RSC a try. I’m going to germ some of their seeds soon just to see rates. And that’s all I got. 
