Using Fake Out at all with Whimsicott on the field, or potentially in the back, is also a painfully bad idea. Even if you fake out -> switch you still lose a turn in that slot.
Meowstic's Fake Out is faster than Kang's; and if that fails, Prankster Quick Guard blocks +6 Weavile's Quick Claw Fake Out. And if that won't work because KhanArtist, you just Protect -> Safeguard and invalidate Smeargle's life.
Been running Prankster Safeguard longer than VGC16 existed, Fake Out has existed since long, long before then too.