Have a look - ie Google - the stone watermill at Little Salkeld in Cumbria. Nick, there, is a particularly helpful individual (if he's still there) and it would be useful to run your theory past him. (He's been producing lovely flour for thirty years).
In a strange way I have sympathy with your view - I believe the potter's wheel was in use here long before it is accepted that it was - but there is little or no supporting evidence. What we have - querns and worn down teeth - suggests that milling grain was a kitchen enterprise. And I've done it - remember the old Corona mill? No wind power neede there, just a sturdy table and some elbow grease ...
here's another test to see if the ancient people ate grain ground on sarsen stone. perhaps there is some specific trace of sarsen minerals in those very same ground down teeth.
more to think about
clyde