You are presuming to know the mind and ways of God. God could just as easily have devised creation with an infinite number of possibilities. Your way of thinking is forcing God to one choice, one solution. In your paradigm, God's plan becomes a necessity to which God Himself becomes a subject. That makes His plan higher than God.
We know that God gave man the ability to choose. Man made a fatal choice. God offered Adam a chance to repent. If He wanted Adam to fail, why did He even give him a choice? Or offer him to repent?
God revealed to us that He desires that all men be saved. His plan is an offer to all mankind to be restored to our original state. That much was revealed. The rest is a profound mystery.
I am simply affirming the bible, and the historic Christian truth that God is omniscient.
If God is omniscient, then He knows everything with zero exceptions.
God did not want Adam to fail, but God knew that Adam would fail. God carried through with the plan because the Creation declares the Glory of God. In particular, it declares the glory of His grace in Jesus Christ, the central event of all that there is.
It is not possible for God’s decisions to subordinate God. Since God is all-knowing, God made an all-knowing decision to initiate THIS creation, as opposed to a different creation.
It is proceeding according to plan.