I'm not the one here claiming any particular origin to the Universe. You are.Sure, just as soon as you sort your nothing out.
So why do I have to have an alternative to your "prime mover" before you defend it as the only valid origin story?
Defense attorneys in a murder trial don't have to identify an alternative murderer in order to have the case decided in their favor. All that is necessary is for the prosecutor to fail to make a case.
If you can't make your case for your "prime mover", John, you automatically lose. No alternative case is required. Your case stands or falls on its own.
And since you can't seem to produce any evidence for it, your case falls.