So, the hub is mounted to the control arms, and the control arms move in an arc... so if the shock were attached to, say, the lower control arm between the pivot point (frame) and the hub (outer-most point of the control arm), then it certainly makes sense to have a hub/control arm tip total travel of 12+ inches with a shock stroke of 8 inches. Similarly, a relatively minor increase in shock stroke length would have an amplified effect on hub/control arm tip travel.
That said, if there are other gubbins that get in the way and/or bind up, then all bets are off, regardless of shock stroke.