Yeah thats one of the things I love about bicycles. Im not tall and my legs are rather short, so even though I have great lungs I just cant keep up with tall people while running. Bikes are like a bit of an equalizer.
I'm not an expert in sports science or physiology but I think that is largely a cardiovascular thing. Or, at least, it hasn't much to do with muscle shape and size. Anyway, you might find that their inner physiologies to be quite similar despite the differences in body shape. Just my guess.
Yeah I was thinking the same thing.