From what I've seen and read about Tenkara flies, matching the hatch does
not seem to be an important requirement for their design and use.
The same seems true of the Italian Alpine flies.
This is because of the speed of flow in the mountain streams, the fish have to be quick if they are going to get anything to eat.
So if you are going to use your Tenkara rod on your home streams,
in which Traditional Wet flies, Spiders etc catch fish, then there
is no reason to use specialised mountain stream flies like the
Tenkara or Alpines. No doubt you will catch trout with them but the are not 'magic' flies.
And if you already have a good collection of Spiders etc, why spend good
money to no avail, or not much anyway.
always remember 'mony a mickle mak's a muckle'.