There are no 'sling rings' in the comics. That was invented for the MCU to demystify magical teleportation and align the magic users with the tech-oriented superheroes and make them more acceptable to the superhero fans. Likewise, the Eye of Agamotto is not an Infinity Stone in the comics. It's a purely mystical amulet.
I recommend the following to get a better understanding of Cumberbatch's range as a performer: Both filmed versions of the British National Theater's live recording of the Frankenstein play that Cumberbatch starred in along with Jonny Lee Miller. (They each took turns playing The Creature and Dr. Frankenstein); Tinker Tailor Soldier Spy; The Imitation Game; The Hollow Crown, War Horse (good performance/mediocre film), and even his voice acting as Smaug in the Hobbit films. If you like those, you could check for more of his work. He's as good as possible in the MCU films, given how limited those films are in terms of character development and expression. He plays MCU Strange well, but Strange isn't the sum of his acting range by any means.