I don't mean any disrespect, because it is a pervasive mindset with all humans, but the notion that it would be 'extra' for God to do both rather than just the one, is not (in my opinion) accurate. Also, while I do agree that God's way is the most efficient way to accomplish what he had in mind from the outset, I believe it is the ONLY way, as 'other possibilities' are only in our minds. What God does is all that happens, no matter what means he uses to do it.
But this notion is very human —one often wonders 'why God went to the trouble to do x...'. "Why did God put Job through all that; why should he prove anything to Satan?", to which I answer, "among other reasons, so we would have this discussion!"
God is the 'inventor' of time. He can form it and manipulate it any way he chooses, without deceit or paradox, from his perspective. But in fact, there have been for some time now, indications from the scientific community (cosmologist, physicists) that indeed both are possible. He may do both in order to deceive the blind and to make those upon whom he chose to show mercy amazed at his wisdom and power.