I am toying with getting a little more wrist hinge and getting the club working a little more vertical on backswing to help flatten the club on the downswing.
The purpose for this move is to avoid getting too inside on takeaway. I start with my lead wrist fully uncocked (Bryson Dechambeau like).
Am I going to get myself in trouble with an earlier wrist hinge and more vertical club on backswing (think leadbetter A swing). My goal is to work more toward back and down on same plane, but to break old habit, trying to do opposite.
I think I get what Russell is saying. There's a propensity to take the club back too low and flat for some folks when rotating the shoulders in the backswing. That said, Tom's backswing videos cleared that up. The upper area of the left arm stays connected to the pec on the takeaway. At the 9 o'clock position the club face is pointing more downward, and from a DTL view the club head appears outside the target line. But as the shoulders rotate back, NOT an arm swing, the club head travels to where Tom shows in his videos.
If someone comes from taking the club too low and inside, this will feel more "upright", or "vertical". I got into a "too flat" backswing and started to get my right elbow stuck on my side on the downswing.
In summary, Russell is (I believe) describing Tom's backswing method. It's possible it just took some time to "sink in".