I have a DOVO with single piece horn scales. I like it a lot.
I would not thin your scales down if the balance is fine!
Should you be making another set you can saw them
thinner. Glue the fancy wood to a sacrificial base and
use a circular saw to trim off the thinnest bit then move
it in a little more than the blade+1/8" cut the razor slot
then blade+1/8" and trim off. Perhaps 3/16"
For wood I have a Dovo with ebony scales and the ebony is about
the same thickness as your photo. They look thick
but the balance is spot on.
Summary: it is the balance in your hand that is important.