The truth, in my opinion, is more akin to be infinite realities occupying the same physical location but in different bandwidths of reality. Simply put location A in space time most likely is occupied by an infinite number of reality instances simply stacked in different space time bandwidths. So instead of slices of bread laid on each other, it is likely to be a single slice of bread imprinted an infinite number of times with distinct reality instances all with their own time space bandwidth assignment. The difference between reality instance A and B is more likely more a matter of attenuation than of physicality.
This does not presuppose that space time location A has a physical location correlation to all of them. In fact, the best guess is that the only thing they share in common is the space time bandwidth marker. New York City is unlikely to reside in more than a single instance location. So in one reality that space would be New York, and in another it could be something else altogether with a different name and different organizational principle.
In fact, it is entirely possible that humans may only exist in this instance of reality. In others, bees may have become the dominant species in some. Reptiles may have risen in others. In others dinosaurs may never have fallen into extinction. My fundamental point is this, the idea that there are an infinite number of specific people residing at the exact same time and place in other realities is highly specious. Chaos, entropy, and random chance make this concept a virtual impossibility.
It is highly unlikely that what I am suggesting is entirely new. The best guess is that this is a central tenant of science fiction and that my thoughts are a product of that. Regardless of the ultimate source of the idea, my thoughts do raise, at least for me, some interesting questions.
How are the bandwidth markers assigned? What decides how an item is placed within a space time location? Are the space time bandwidth barriers firm, or can they be penetrated? Can items from one instance of reality travel to another somehow? Can this travel occur frequently, or is there a price to pay for this travel? Can something from one instance reside in another without obliteration? Can it return to its point of origin without obliteration?
These questions and many more occupy my imagination at the moment. I plan to explore it in the future.