many seed sellers selling these landrace seeds are selling just that, they come direct from whatever country
they are not selected or breed in many cases
if you get something from say ace seeds or mandala they are using landraces but creating hybrids from them, or in many cases attempting to
these should be more stable
i would suggest they will show more phenotype diversity than the majority of hybrids , you should take cuttings from all phenotypes
the last landrace i grew was afghani from seedsman, there were many poor low vigor phenotypes that i had to kill off
i was lucky to find a keeper for a while
peace