I suppose one could make the ABC counterpoint to some of these posts, that if Strange has defeated Dormammu more than once, and Dormammu is > Shazam, then Strange should be > Shazam. But of course very, very few people would agree with that, and therein lies the logical flaw in assuming Dormammu's dominance here.
But comics don't work like that. I know very little about either character, so I'm not saying that I just poked a hole in your arguments. Just something to think about.