To change this scene from a horror-filled graveyard to an undead fashion show, you will apply the runway strut animation to one of the zombies in the scene.
However, all the zombies are animated. The runway strut animation you exported is meant to be used on a non-animated skeleton. Thus, you need to replace one of the zombie references with its non-animated counterpart.
The animated zombie is replaced with a non-animated version.
The non-animated zombie model is more appropriate for the strut animation since it more closely matches the reference that the strut was created from. The asset has all the correct published attributes, however the default View hides them from you.
The zombie changes positions. If you play the scene, the zombie walks with the same runway strut as the animated skeleton.