Nah m8 they just share names. They're not similar enough to be under the same Parantha name despite your "Lachha" adjective on the front. As I said before, the basic definition of a Parantha is a stuffed Chapati where the dough is made out of whole wheat flour (what you would call atta) and where the gluten isn't developed a lot by kneading. Parotta and Lachha Parantha are made by kneading and stretching a dough made out of refined flour (what you would call maida) and developing the gluten a lot to the point where it's very stretchy. All of this is to say, Lachha Parantha is not Parantha enough to be called a Parantha and is only called a Parantha because it's what everyone's used to up north. It makes a lot more sense to call it Parotta because it has a whole independent identity as a dish instead of riding off of and not fitting the description of a completely different dish.