Width of stance and speed, vary things. My feet are directly under my shoulders, narrow stance makes it almost impossible to jam anything. You are also confusing weightshift and torque. The rear foot driving/torquing from the ground in a planted wide stance will jam up your lower back. Your rear knee being extended means your torque is spent. Watch any top thrower and the rear knee remains bent/torqued during the swing even when there is no weight on the rear foot.
Yeah, I must be confusing weightshift and the push off the rear foot.
Just so I can get clear: let's define
weight shift as simply the movement of weight from the rear foot to the front foot. (In an X-step this goes from 100% rear/0% front to 0% rear / 100% front. In a standstill throw it may not be quite 100% but it'll be close. And in the dinglearm and other drills, it's not quite as much either.
Let's define
driving the hips as the linear shift of the hips in the direction of the target that gets your front femur locked into the hip joint and hence your momentum braced behind the inside of your plant leg. This is like 1-2" inches of shift, but it is crucial.
Let's define
rear leg push as the force in the direction of your target generated by pushing of the instep/ball of the rear foot. This can be a pretty powerful motion, as there is a lot of stored energy here (if you are braced against the rear leg in the backswing) that can be transferred upwards leading to an explosion of power into the disc. (I think this is what SW22 is calling "torque".)
Let's define
clearing the hips to be the clockwise (RHBH) external rotation of the pelvis from in-line to the target to faced up to the target that happens naturally as a consequence of proper bracing / pivot /follow-through.
Finally, let's define
lag to be the differential between the lower body rotation and the upper body rotation. The more rotated your lower body is while your upper body is still in the backswing, the more "lag".
Okay, so I want to know how all these concepts work together in a proper throw. The way I'm currently conceptualizing it: is that basically the rear leg push does everything else. It causes the weightshift and the drive of the hips simultaneously, which puts you into a braced position. If you have just the right amount of lag, this force from the rear leg push travels up the brace until your hips clear and the momentum syncs up with the shoulder swing at the right time to explode onto the disc.
But a lot of things I've read, and seen on video, etc. seem to suggest that the weightshift and rear leg push are somewhat independent of one another. Almost as if an early weightshift starts the throw and sets you up for a powerful rear leg push and simultaneous drive of the hips. If a rear leg push into the weightshift means your torque/power is already "spent" then it seems like it'd need to be delayed.
Of course, there must be some level of push into the weightshift or else it wouldn't happen (right?). And obviously if 100% of your weight has already shifted, then your rear foot is effectively off the ground and you've got nothing left for the rear leg to push.
So how should I be thinking about this?