An interesting observation is how much roll back to vertical a player has from release point is dependant on the angle of the inclined plane and where the vertical plane of the hinge action intersects it.
The more flat the plane angle the more accumulator 3 you will need in conjunction to load both itself and #2. The hinge action plane from the point of the left shoulder isn't affected by the left shoulders own movement - global application rather than local. With the swingers horizontal hinge action - accumulator 3 will be loaded the least when the vertical plane intersects the inclined plane parallel to the plane line....the most when it goes through the plane line at 90 degrees.... Accumulator 3 is constantly adjusting in accordance to the plane and how far out of line it is with the vertical plane of the hinge action.
For any given point on the inclined plane - maximum no.3 will always be when no.2 is fully loaded also....
I fight a similar problem and I think mine stems from not executing a proper sequenced release. By that I mean that I often end up with angled hinging even though I classify my motion as a swing. It may be that I'm still in the non-automatic release stage of refining my swing, but for some reason I occasionally (and quite unintentionally) use a simultaneous release motion which usually results in what I call a "wipe" or a push, or a push-cut (unless of course I accounted for it at setup with a slightly closed face). I think Homer called it that "wilted" feeling, although I believe he used it in terms of not getting the right arm straight just after impact. (As I think about it, not properly executing a simultaneous release may indeed prevent the swinger from not getting full right arm extension as the clubhead may not exert as much "pull" if #2 isn't allowed to get fully released).
I just seem to get a better roll when I deliberatelyuncock the left wrist on the downswing. And it seems like the sooner in the downswing I do it, the better the result. For me I think it's the old "feels as if" thing. If I feel like I uncock right from the top it actually happens where it should. I get a much "heavier drag-your-wet-mop" feeling when I really try to deliberately release #2 in the downswing. And with the shorter irons I think there is a tendency to hold off on that #2 release as we try and over-control the face and ball flight direction.