also, phenos can vary a lot of you back cross a cross of 2 different strains. when you first do it, you get plants that are mostly in between the two original parents, but when you back cross, you get a full pheno expression with a wide variety of offspring with a mix of each parents traits. when you back cross & select enough times though, then you stabilize a strain and have something that will "breed true" like the original IBLs (in-bred land races) that were the original building blocks of everything.
you don't want to keep in-breeding though. once you stabilize a strain, in-breeding will eventually lead to genetic waning the same way keeping a clone mother too long or taking clones of clones can happen making you need some fresh new genes to restor hybrid vigor.