It’s not like they are just going to do a visual spot check on each level to clear out the AI assets. They will probably tag it in the meta data as a placeholder. So some automated validation process can find every ai asset in a level. Not to mention game objects are wrapped in an object template. And then the template is used to place the object into the scenes. So they only have to replace the placeholder with the final object once in the template and then it will replace it everywhere the template is used.