I think it is generally accepted that the standard ratio for cookies is 1:2:3 by weight (1 part sugar, 2 parts butter, 3 parts flour.) And you can actually get a decent sugar cookie using simply that ratio of those three ingredients (I have a Turkish Butter Cookie recipe that does just that!) If your recipe calls for an egg, it might include some extra flour. If you add additional fat (like peanut butter, for instance,) you would likely want to decrease the butter. Same with sweet add-ons (like chocolate or butterscotch chips)...you might, then, have to decrease the sugar.
Usually, the less you mess with the dough, the better, as too much handling can result in a tougher cookie. So, it seems reasonable to me that a recipe that calls for rubbing the diced butter into the flour could result in a pretty dense cookie--with the possibility of getting air pockets in the structure of it, as well. I have actually never heard of using that technique for making cookies--only for biscuits or pie crusts. So that's a new one for me.
But again, I am no expert. Maybe trying a few different recipes will be your route to finding what works best for you. Good luck!