Just to reiterate what Peter is saying:
You can write something either in AS or JXA, that loops through all the images in a folder (for instance), and creates the KM actions automatically.
So when you need to change an image, or add more, or whatever, all you have to do is re-run the AS or JXA code, and it will re-create all your actions.
And actually, you could write most of it in KM. If memory serves, you can do everything except actually creating the actions.