You can’t “move your given nomination from one SA to another” the nominations are given for specific academies; if that is what you are asking.
If you haven’t already had interviews for any MOC you can inform the interview panel that you received a WP nomination and would prefer to change your first choice to a different academy. That will likely lead to some tricky questions you will need to be able to answer.
It is not a bad thing to have multiple nominations to one SA even at the risk of having none to another. Especially if you have a strong preference for one of the branches of service (and since you put WP as your number 1 and AROTC as your back up, it would appear that you do). Multiple nominations give the SA more opportunity to find a spot for you. If that is your authentic desire; that is where you should probably put your effort.
To answer your question, there are very few paths to an appointment without a nomination. The SA do have a few options that they control but they are used sparingly. So do you have “a shot” at another Academy? A very slim, almost non-existent one. Congratulations on your WP nomination and your plan B college acceptance!