That would be one theory.
He knew that Adam would disobey, he knew that man would fall.
That would be another.
It was all according to his purpose, his will.
That would be the first one again.
Before the creation of the earth, God had a plan that his Son would save the elect. Before any sin happened, he had a plan.
That would be a third theory, somewhere in between the first two.
You don’t believe that God had a plan?
By the way, not theory, but scripture.