Regardless of the true mathematical odds, this seems to be an increasingly common occurrence for me. I read this thread earlier and immediately thought of how just the other week, two stations were not only playing the same Smashing Pumpkins song (whatever the one is with “Today’s the greatest…”), the song was playing at nearly the identical time. They were maybe 10 seconds apart.
Then tonight, while on a drive, I heard Paramore’s “Decode” on these same two stations, about 30 seconds-1 minute apart.
These two stations are similar, but one is decidedly more hard rock than the other (which is poppier). Still, they do seem to share quite a bit of the same music catalogue.