So we can see stuff at z=13. What I can't get my head around is that the Milky Way either formed around the same time, 13 billion years ago, or it formed from

So we can see stuff at z=13. What I can't get my head around is that the Milky Way either formed around the same time, 13 billion years ago, or it formed from stuff produced by galaxies that did. But we can't see the primordial Milky Way by pointing our telescopes at z=13. These old, faraway galaxies must have been formed just faraway enough from where our galaxy formed, that the expansion of spacetime has prevented their light from reaching us until "just now". So I wonder what distances apart the places where the primoridal Milky Way, and these two distant galaxies, must have been for the light to take so long to reach us. Like, the Universe was a lot smaller then; galaxies were much closer together. Galaxies at z=13 must have formed shortly after the Dark Age ended, and the Universe became transparent - like a few tens of millions of years - less than the time since the dinosaurs were knocked out (I'm assuming galaxies can't form in a plasma Universe, but maybe I'm wrong).