[C4] Two plants look much different.

This is called phenotypic variation. Not all strains are as uniform as others. E.g., some have 2-3 phenotypes and some may have 10+ This gets into the whole issue of breeding, selection, and stabilization of any strain. Welcome to cannabis growing :) There are tons of resources out there if you choose to educate yourself on this topic and pursue more knowledge. Knowledge is power. You will be a better grower, even if its just for fun, if you start to geek out a bit on various grow and breeding techniques. Good luck and you have healthy plants going for you. You may find you prefer one phenotype over the other, or that they have entirely different terpene profiles, etc., and that’s part of the fun of figuring out not only which strain you like, but which phenotype within that strain you prefer. Good luck! Keep up your good work you are doing something right.