There's one more point which comes up and I believe it's significant.
You would never buy a pair of shoes 4 or 5 sizes too small and wear them.
Likewise, you have to make the knife handle of a size to fit your hands.
I understand that the handles of tennis rackets are to be judged in the same way.
Scattered here and there in a variety of literatures published by Kestrel Tool (aka Gregg Blomberg).
is what I have come to call the "Kestrel Constant."
"Palm up and fist grip on the knife handle,
the tips of your second and third fingers should just touch the ball of your thumb."
After some experiments carving prototype handles in easy wood,
I learned that I need a starting handle blank of 7/8" x 7/8". Even applies to adzes.
I learned that I can hold as big as 1" and as small as 3/4" relaxed, not with a death-grip.
My old hands are showing a touch of arthritis.
Tool handles bigger or smaller than my size range actually hurt to hold after a while.
Anyway, anything out of that size range is something that I really notice.