Don’t forget that Doctor Strange analyzed all of the 14 million possible ways the Avengers battle with Thanos would have resulted. Which also means that he has deeply analyzed every single step that is a part of the solitary victorious timeline which would ensure Thanos’ defeat. Therefore, he can plan with this foresight. Therefore, it is not illogical that letting Thanos kill himself and half of the universe is also one of the things which would eventually result in Thanos’ defeat.
Although it seems to be terrible, it might be necessary. Just recall the absolutely gut-wrenching death of Peter Parker, and the impact it would have made on Tony Stark. Such an event would make him resolute to take revenge and stop the Mad Titan as well as any other plans that he had for the universe. This is even more evident when you see that Doctor Strange handed over the Time Stone to Thanos to protect Tony’s life, despite having spent only a few hours with him. It means that in the one victorious future timeline, Tony Stark must be crucial for saving all and beating Thanos.
Fans had anticipated that Doctor Strange would use the power of Time Stone to take the events of Avengers: Infinity War to a step back. Thanos created the Gauntlet, but, since Strange is dead, that might not be possible. However, after the initial attack on New York by the Black Order, Wong came back to the Sanctum Sanctorum whereas Doctor Strange was held captive on board the ship of Ebony Maw. He has been proficient in mystic arts for much longer than Stephen Strange and had been in charge of the various restricted books at Kamar-Taj library. Therefore, it is possible that Wong has the know-how of Time Stone’s working or he will learn it quickly.
However, he needs to recover the Time Stone from Thanos to do that and his powerful Infinity Gauntlet. Difficult, but, not impossible. While we didn’t see him enter the Astral Plane, what if Doctor Strange had relayed a message through it to Wong? Because when Strange talked to the Ancient One before she died in Dr. Strange solo, she slowed down time to nano-seconds to have a lengthy talk with him.
Doctor Strange might have succeeded in communicating with Wong and to inform him whatever was necessary to win, and he is not averse to make daring sacrifices. (Dormammu, I’ve come to bargain..). If the sacrifices made by Strange result in Wong managing to turn back time and undo the damage, he might be instrumental in saving the Marvel Cinematic Universe.
Joe and Anthony Russo directed Avengers: Infinity War is currently playing in theaters and the movie stars Robert Downey Jr., Chris Evans, Chris Hemsworth, Mark Ruffalo, Jeremy Renner, Scarlett Johansson, Paul Bettany, Anthony Mackie, Paul Rudd, Elizabeth Olsen, Tom Holland, Benedict Cumberbatch, Chadwick Boseman, Chris Pratt, Zoe Saldana, Dave Bautista, Bradley Cooper, Vin Diesel, Tom Hiddleston and Josh Brolin, and others.