I'm only speaking to my experience. Rightly or wrongly, based on my perception of what Miller, Nicklaus, Weiskopf
did, I played with a weak left hand grip and tried to fade everything. Feeling was high hands, and then fall down through the swing. When it worked perfectly it felt like I hit it with the heel my left hand with no effort to manipulate the arms or the wrists. I rarely ever hit it left, but could draw the ball out of trouble.
"I have to disagree with that last sentence.
I believe weak grip players tend to "hold off" rotating the forearms and use the upper body particularly the left shoulder girdle for torque.
Strong grip players tend to have tighter forearms and use the wrists and forarms to promote the rotational force on the club.
Typically but not always the stronger grip player has relatively bulker forearms,whereas the weaker grip player tends to be broader shoulders."
Interesting. I was tall, flexible, loose, 6'3" with broad shoulders. Thin wrists, etc. I haven't thought about it before, but 'hold off" certainly describes my swing even now. I'm still tall with broad shoulders. The other two adjectives have changed just a little!