It depends how smart the player you are facing is too. If they predict "Oh, this is probably your standard Ludicolo" and then all the sudden it's a Sword Dance Ludicolo, who then proceeds to sweep your entire team when I switch into your Physical Wall to force a "implied threat switch" my gimmick has succeeded, and I will now destroy your entire team.
Basic things like that. Some pokemon just have that implied "factor" that says "Oh hey, my most common set is [insert standard set here] and I just switched in like I'm an actual threat to you. Maybe you should switch out to a [supposed] counter of this [supposed] set.
It's all just a possibility guessing game. Nobody knows what you are playing as, as long as you can successfully pull a "fake threat" move.
For anyone who knows my boyfriend, he is well known for doing such "gimmicks" and pulling them off flawlessly.