Well, what I'm saying here is what kind of subtextual logic do you need as a reader to justify your willing suspension of disbelief? For the time you spend engaging with the fictional world as presented to you, that is. If your mind tells you there's only one set of physical laws that apply to the universe, and that needs to be true for both the real world and any fictional universe you're reading about, then you're probably the sort of person that doesn't enjoy science fiction and fantasy stories, or a the very least, you're one of the subsets of SF fans that insist on only the most plausible speculative fiction of the "hard sf" type. That would probably severely limit the sort of entertainment reading material available to you in graphic story form.
Every reader has his or her own limits regarding the boundaries of the kind of fictional premises he or she is willing to accept in their entertainment reading. For me, it's just easier to use the broadest theory that accounts for the greatest variety of sf/f-type comic book story premises that I like, i.e.: it's a parallel universe different to our own, in which the observed phenomena doesn't match with the physics of the world WE live in. Therefore, it's probably a universe bound by its own set of physical laws, different from the laws we know in the real world, that allow what we see in the story to happen (it just saves having to chuck a lot of what you see down on the page out the window). And if it's Slaine, or Conan, or Dr. Strange, then the laws of physics in effect in the story might be something so alien to our own that we just call it "magic". Either that, or as Arthur C. Clarke said, it's a kind of science so advanced that it's indistinguishable from magic.
And if it's conflicting story data from 2 or more stories supposedly set in the same universe, then you have to synthesize your own personal headcanon, by deciding to embrace some bits and chucking out the ones that you don't like or which seem less consistent with the bulk of story data you have.