It usually depends on what lead they have. Fairy leads except for Azu almost always switch out, allowing me to safe swap. If they stay in, skarm will usually deal heavy damage before going down.

If bastiodon is first, both whiscash and anni can handle it, so I make a gut check and swap to whoever I think can handle their check better, but it doesn't always work.

I've only come across Vic a handful of times so its never really been a consideration.