At one time I believed this was an original thought, but I'm sure it's been stated by actual baseball people a thousand times. Assuming it's true.
But isn't the size of hands/fingers on a pitcher the ultimate difference maker?
It's what made Koufax remarkable...what allowed Pedro to dominate despite being undersized. I always thought it's why guys as tall and angular as Chris Young often can't throw 90. Same with some guys that tall and 240 pounds of muscle. The last leverage provided by the snap of long fingers is what adds the 'sizzle' to pitches.
If there were a counterpart of the NFL combine in baseball, I'm thinking the length of fingers for a pitcher would be the most important thing measured.
Anyway, this is either daft or common knowledge. You just reminded me of it with the Odell reference.