I think there's a confusion about what an act is. An act is when you pretend to be something you're not. Pickle pretends to be this dim bulb, second coming of a third rate Jessica Simpson with a country twang. Is she that stupid, that much white trash? From what I've read online about her, while she's not the sharpest tool in the shed she knows that the stupid blond act works and the fact that we can pretty much all tell that she's going for the stupid hick act just proves that she sucks even at that.
Chris has a very distinct personal style... in the way he sings. When he talks he doesn't resort to some shtick or an angle, at least not in the shows I've seen so far. What pray is his act? The fact that he sings rock? Singing a balad, and singing it a bit more straight up country to do it justice, doesn't mean he's putting on a new act to please the country demographic. It means he can sing country if he wants to or he's forced to.
Pickle needs her act because she can barely sing anything, even country is a hit or miss for her. She is now identified with her gimmicky image, and should she suddenly decide to lose it as of next week, I bet she'll be voted off in the blink of an eye.
From what I can tell the only person with a real act on the show is Pickler. Even Paris, as bad as she is, is just pretty much this young girl with an annoying voice. I don't like Bucket either but I don't feel that he has an act the way Pickle has. They all appeal to a certain segment of the voting public but that doesn't mean they're pretending to be something they're not.