Great article here on aligning your nymph setup in the right lane especially when approaching water and trying to find the strike zone!
I can say I’ve been with different guides that take different approaches. Fishing the Smokies had more of a Polish style approach to bug setup (meaning get it down fast and typically have your weighted fly at the top, even with extra split shot, given most of the waters we fish in wild settings is shallower here in the southeast, while my unweighted fly is at point about 18″ to 24″ off the weighted… though I usually start with my weighted fly at point and then my unweighted at the top), while Big T takes more of an approach as listed here in this article link.
The Polish method uses two flies with the heaviest fly in the “point” or bottom position and the lighter fly in the top position. There is an instance when you want to reverse these two flies and that is when you encounter shallow water, holding fish. By moving the heaviest fly to the top(dropper) position, it allows you to achieve better drifts through that shallow riffle or run and not hang up on the bottom as much. It will also allow you to keep all of the flies in the water vs. one being lifted out of the water while you are trying to keep the drift going
Pick what works for you given water conditions and most importantly confidence. Some great approaches here for sure.
Enjoy!