I’m tempted to fish this as a rockworm pattern. I think I will tye some with a black head and darker legs (perhaps starling hackle), to match the color of my local bugs.
Not a doubt, your pattern will catch fish.
Ron - I fish all kinds of flies with my tenkara rod. Even streamers. It all comes down to how you present and what you do to manipulate the fly to bring it to life. That was one of the fun things about learning how to fish with the tenkara rod. Without being able to strip line in to animate the fly, it becomes necessary to move/twitch the rod tip. I feel that I spend more time fishing (keeping the fly in the water), and can get longer drifts (dictated by the stream current) and observe the fly more closely in the water (sight fishing became a bigger part of my approach). I love being able to watch how a fish responds to a fly (or streamer), since it teaches me what they are after. What kind of action (or lack of action) causes them to respond.
Smallmouth bass are especially fun, since they act like cats. Drift a fly motionless for several seconds, then twitch it into motion. BAMMM! A bass pounces on it without hesitation. They are also blast to fight on a tenkara rod.