And, I called it! Didn't I say last comic "as if one Moondancer wasn't bad enough"? x2
...and then she decapitated the fake; THERE CAN BE ONLY ONE!
Seriously though, while I was fully expecting the identity crisis to get resolved this easily due to best pony's distinctive speaking habits, it was no less amusing. Of course given this comic's general tone and themes just because they can easily discern which Moondancer is real doesn't necessarily mean that the Tragic-Six will have an equally simple time deciding which Moondancer they actually want to keep. Well actually the answer is pretty simple, NIETHER, but I'm sure they'll keep at least one of them anyway for some reason or another.
Clearly, they need her around for all her star power. She's the only one of the Tragic 6 who's made any sort of name for herself outside their little circle.
She's like the Anti-Sparkle, but famous for her skepticism of Celestia rather than her fawning apprenticeship.
Now if only her fans could figure out what Moondancer looked like, maybe the party could actually make use of that somehow.