The hands obviously hold onto the club and play a major role in the club face control. If you have a good grip position, your club face has a better chance of starting the ball on the line you intend it to start on.
The hands were not meant to be used for swinging the club with the intent of rotating the club face thru the impact position. This requires extremely accurate timing and unless you have a physical dysfunction, which precludes you from moving your body or your arms, it is not recommended!
The hands play an intentionally inactive role thru impact to the finish position, the picture below displays this correctly. The 2nd picture displays active hands/wrists, which lead to poor contact, directional issues and lack of consistency. If you are using too much hand action, start turning your body and swinging your arms more to the finish position.