Like87, legit12, wOW5, lOL3.
There is insufficient independent motion of the two arms (due to an independent movement of the humeral heads within the shoulder socket joints while the shoulders are rotating) per unit time during the takeaway that will allow the hands to avoid being pulled inwards too.
If the left arm flying wedge alignment is intact/correct and a golfer has a geometrically FLW, then the clubface should be parallel to the back of the left forearm.
The plane or space that the swing travels through during the approach creates the angle that the ball will travel on at the release point. .So first, lets talk about what we mean by a straight swing. .Note that Aaron Baddeley's hands are outside his right foot, and in line with his toes.Also, note that the left upper arm is still lightly connected to the pectoral area of the left chest wall without being over-tightly connected to the chest wall.I have drawn a yellow line through his right elbow at address, and that represents the elbow plane line.A golfer should only apply enough extensor action to keep the left arm comfortably straight (and not rigidly straight), and there should be no sense-of-tension in either the left arm or right arm.
Image 2 shows Tiger Woods when his left arm is parallel to the ground in the backswing.
In a DTL view, one cannot see that the left arm is straight-in-line with the clubshaft (because that requires a face-on view).

Also, note that the butt end cardfight vanguard card game review of his club is pointing at a point on the ground that is outside the ball-target line (yellow dotted line)."Never Slice Again!" video.VDXU_IC1qpdw Dustin Johnson has a superb golf swing and he uses a RFT backswing action.Reverse slot backswing action - capture images from a swing video lesson 6 Note how the golfer takes the club too-inside at the start of the backswing (image 2).V12KHR1xr2SA Note how his golf students simply turn around their rightwards-tilted spine.That means that a TGM hitter is not using a takeaway swivel action, which means that there will be less external rotation of the right humerus, and less pronation of the left forearm, in the early backswing (when compared to a TGM swinger).By Rick Wiltse, Coach at the Kegel Training Center.Perfect Pivot - Part 1: Backswing Pivot.If the clubhead is high off the ground at this point in the takeaway, it either indicates that the golfer has flexed the arms (instead of keeping them straight and/or cocked-up the left wrist, and/or tilted the upper torso to the left (called a reverse.During the RFT backswing action, the clubshaft is going to become progressively more closer to being straight-in-line with the left forearm, and the bent left wrist will flatten slightly and become a geometrically FLW by the end of the takeaway (image 3).Therefore, the golfer is forced to lift his hands up to their end-backswing position during the remainder of the backswing action - by elevating his left upper arm upwards across the front of his chest wall.

Note how his left arm is lying along his shoulder turn angle, and note that his power package is correctly assembled (right forearm flying wedge has the correct supportive relationship with respect to the left arm flying wedge).
Note that he doesn't upcock his right wrist very much during his backswing action (like Ryan Moore ).
At his end-backswing position, Stuart Appleby's hands and clubshaft are behind and slightly higher than his right shoulder, and they are both on the * turned shoulder plane (TSP).