I have always talked about the similarity of baseball and golf motions. The only difference is the ball sits or is thrown in a different area relative to the ground level.
Speed and control come from proper use of both arms. The left arm/hand should be classified as the rudder that steers the ship (the clubface) in the right direction. The right hand and arm supply extra power.
Can the body orientation cause you to mishit your shots? Absolutely!! In this video I explain how some instruction ideals may actually be hurting your swing rather than helping it.
Lowpoint of the club is actually different to the strike point of club and ball. In this video I show why many golfers produce such an array of poorly struck shots.
A question I often get asked- Is why the forearms? This video will clear up why that is the focal point of the release rather than the hands themselves.