I didn't make the comparison initially because I was on a long-haul flight and was completely exhausted, but the parallels between Iron Man and Doctor Strange are pretty obvious now.
It's spelled out pretty clearly in the latest Honest Trailers, which even points out the similarities between Doctor Strange's watch (which has an engraving on the back) and the gift Pepper gives to Tony Stark.
I used to be excited for superhero movies. But this is kind of how it is now: constant repetition of the same overarching themes, with the heroes/protagonists/supporting characters/locations swapped out at will.
That said, Doctor Strange was visually enjoyable to watch, although it hasn't inspired me to read the comics one iota. Maybe I need to start getting into more anime again.