Kevin Feige spoke to Comicbook.com back during the film's production and explained how Scarlet Witch's power differs from Strange.
Said Feige, “Her powers, she’s never had any training, I’m talking about Scarlet Witch. She never had any training; she’s figuring it out. Arguably, you could say that that’s why her powers are much more chaotic and much more loose in the way that we showcased those light effects. In [Doctor Strange], some of what you might see today, even the cover of Entertainment Weekly, it’s much tighter. It’s all about focus. It’s all about pulling energies from other dimensions in an organized and purposeful fashion, which is why they can do a lot more than she can in, at least, a much more precise way.”
Is this a hint that Scarlet Witch will wield Chaos Magic in the MCU? In the comics, Doctor Strange was surprised to learn that Scarlet Witch used this specific form of magic as he and other Masters of the Mystic Arts believed it didn't exist. It was this ability that let Wanda rewrite reality in the 2005 limited series, House of M.
Besides Strange and Maximoff, we have also seen various Asgardians such as Loki, Odin and Frigga. The first Thor film attempted to classify their abilities as simply very advanced science but perhaps the inclusion of Strange in the MCu will lead to a retcon of sorts?
ABOUT DOCTOR STRANGE
Dr. Stephen Vincent Strange is a Marvel Comics superhero created by Steve Ditko, who first appeared in Strange Tales #110 (1963). A gifted surgeon, Strange suffers irreparable damage to his hands and journeys all over the world seeking a cure. Eventually Strange ends up at the home of the Ancient One and begins a journey into magic and alternate dimensions , ultimately assuming the title of Earth's Sorcerer Supreme.
MOVIE SYNOPSIS: “Doctor Strange” follows the story of neurosurgeon Doctor Stephen Strange who, after a horrific car accident, discovers the hidden world of magic and alternate dimensions.“Doctor Strange” is the latest film in Phase 3 of the Marvel Cinematic Universe. Phase 3’s goal—over the course of four years and nine films—is to introduce audiences to new heroes and continue the adventures of fan favorites.