I've always kept tops and bottoms of rings matched. I learned this a long time ago. As for the torquing, I always alternated my tightening of the screws. Truth be told, most people overtighten the screws on the rings. They really do not need all that much torque. If you have a decent "man" grip, a bit over finger tight (with a screwdriver) is all that is needed. I normally go more myself. You just have to be careful not to crush the scope tube.