Who do you want to be ? The guy loading his head over his foot
(narrow step width), or the gal loading the head and COM inside the foot (less narrow step width) ?
It is not hard to suspect who is gonna be faster and more powerful from these photos. This however does not mean on is more durable, more or less injured, more or less efficient but logical debates and thought experiments can be made here.
The lady is stacking the knee over the foot, the hip over the knee and stabilizing the hip and pelvis sufficiently and durably to keep the pelvis level for the next powerful loading step, and the other is flexion collapsing into the stance phase knee, insufficiently loading the hip and thus dropping the opposite side pelvis. He is not stacking the joints, there is a pending cross over (look at the swing leg knee approaching midline with barely any knee spacing, thus guaranteeing a cross over step or at the very least a very narrow step width.)
Sure, some one is going to say one is a distance runner and the other is a sprinter. Yes, and our point is that the sprinter is not head-over-foot, the one with all the highly suspect flaws is head over foot ! Wider step width means more glutes. Go ahead, walk around right now with a very narrow step width and see how little efficient glute contraction you get, then walk with a notably wider step width, and you will see wider means more glutes. Keep your COM moving forward, not oscillating back and forth sideways over each stance foot, that is a power leak.
The distance runner appears to be demonstrating less optimal in technique, appears is the key word here. Say what you want, but a decent argument might be made as to one of these runners being weak and very likely at greater risk for injury, the other is suspect to be strong and durable, and likely at less risk for injury.
If you ask us, but what do we know . . . . it is all a thought experiment, but based on some pretty decent ideas.
So, again, was ask . . . . which one do you want to be ?