[dlam]

I've tried to grip the club like this, and find it so unstable with the right hand. With the right hand, are you "gripping" the left hand, or the club?

My right hand covers my left hand. The only part of my right hand grip touching the shaft is my right middle finger and a bit of my right index finger at the 1st knuckle.
Even though my right hand is holding mostly my left hand I feel like I am "gripping" the primary lever assembly(left arm and clubshaft) 6-A-2.

Double overlap works only if I have a strong left hand grip. If I weaken my left hand for whatever reason, then I revert to grip with interlocking or 10 fingered.

Curiously, I find the vardon grip to be least desirable. I feel the need to either interlock to stablize the grip, or double overlap to stablize the grip.