jross--My view is that in the freestone waters of the Smokies (inside the Park and out), when dealing with wild trout, presentation is always more important than pattern. These streams are not overly fertile and as a result trout have to be, to an appreciable degree, opportunistic feeders. If there was one tip I would give to the serious Smokies' angler, it would be to focus on precise presentation and drag-free drifts.
That being said, you should by no means ignore the matter of pattern. There are times when it makes a world of difference, but those times are but a small percentage of the entire amount of hours you are likely to spend fishing. If a hatch comes off by all means observe and try to match it; otherwise, pick a pattern such as a Parachute Adams, Cahill, Adams Variant, some type of stimulator, or, in season, a terrestrial for the surface and something like a Prince, Copper John, or Tellico beneath the surface.
Tailwaters are a whole different story, and there pattern becomes of great importance.
Those are my general thoughts, and I'll go back to the beginning--learn to case with great precision at distance up to 40 feet, add to that the ability to read water well, and you are on the road to success in the Smokies.