Tenkara places more emphasis on technique rather than gear. One way to simplify is to reduce the number of fly choices and try different techniques.

In Japan I’ve had the chance to learn tenkara directly from some of the renowned masters of the method. Over the last 4 years I have used only one fly pattern all around the world while chasing trout, and I have successfully caught trout along the most experienced anglers in the country. I have synthesized techniques for tenkara and fly manipulation methods I have learned in this video:
1) Dead-drift: allow the fly to naturally drift with the current
2) Pausing: move the rod tip upstream from the fly to pause the fly in place for a couple of seconds in spots where fish are likely to be, such as in front of rocks.
3) Pause-and-Drift: Put the rod tip upstream from the tenkara fly to pause it for a second or two, then let it drift, pause it again, let it drift.
4) Pulsing: with a rhythmic motion move your fly up and down, making the tenkara fly pulse with life. The tenkara fly will open its hackle when you pull it, but close a bit when you relax it.
5) Pulling: this is a bit like using your fly as a streamer, where you will impart a lot of action. Part of the tenkara line must be in the water to serve as an anchor as you pull the tenkara fly across or upstream about 1 1/2ft at a time. It is particularly useful in faster or higher water conditions.
6) Plunging: This is a technique that may be combined with any of the previous 5 techniques and is used to help sink your fly without using any weight, using currents instead. Cast upstream from a place where the water drops, plunges or gets chanelled between rock, as the fly hits the part where the water is more turbulent, let some of the line into the turbulence to take it down. If you’re doing it correctly and hitting a good spot, your line will seem to stop for a couple of seconds, then it may move in circles a bit, and then it will move downstream, typically fairly deep.