One of my weekend golfing buddies has been taking indoor golf lessons using video. He has been improving. One of his faults is a slight cast when starting the downswing which at times will cause him to pull his shot IMO. Last week he was fit for a new set of custom clubs at the indoor facility. The fitting professional told him he could increase the lag of the club head at impact if he went from a D2 to an E0 swing weight. He said when he swung on the video machine with the E0 swing weight his swing looked a lot better.
Could increasing the swing weight help this swing fault?