TWOK hangs on a dozen too-convenient coincidences, including: Reliant can't tell one planet from another,
Hey, it's just standard practice! You always navigate a system by simply counting the off the planets as you approach the primary. Nobody expects "VI" to go missing, so of course you're going to think that "V" really is "VI." Them's the breaks! Space flight involves risks that can't be minimized.
Suppose that aliens are approaching our solar system shortly after Uranus has exploded. [No jokes allowed.]
They'd say "There's #9 [Pluto] ... used to be a planet, anyway. Now there's #8 [Neptune], mark that one off."
He goes on. "Next is ... where is it ... where is ... must be here somewhere, check the charts ... ahh, there it is, Sol #7! Wow, those rings are spectacular! I can't wait to see the next
one, which is supposed to be even better!"
"Hey, quit sightseeing! Our instructions are to destroy #4, which is lifeless, for our experiment."
"Okay, I can see it in the telescope. Didn't know it was blue and had one large moon."
"Shut up and arm the destructor beam!"