If you have sufficient motor control and dexterity, the amount of required practice should be approximately zero. Just calculate the required finger position and bow orientation, pressure, and velocity for optimal production of the desired sound and do that. That is not how humans perform physical tasks though.

> That is not how humans perform physical tasks though

is it not though? wouldn't it just be that our processing center isn't located completely in the skull as we typically think, but is extended to our spinal cord and nervous system? Something is being processed, you're just not conscious of the entire process. This is especially clear to me as a musician: as you're learning to play, you have to be absolutely aware of all of those processes until you can finally just let go and play!