Do WWE wrestlers have any creative rights over their storyline?

Because it seriously seems they don't. Stone Cold and a lot of guys have left for creative differences, and we all know what happened to Bret Hart back in Canada. So my question is, how much freedom of speech does an actor/wrestler has over his character? Can they reject, change or at least discuss anything they don't like about their storyline with Vince and bookers are writers? (without ending in leaving WWE or a screwjob?) My ideal would be the wrestler, the bookers the writers and Vince brainstorming for character ideas on a round table until they reach a point when it bennefits everyone. But my realistic image is just Vince and the writers having all control "you work for me, you do what I say and if you're not happy with it you're fired" How do you think it works? Shouldn't wrestlers have SOME freedom of speech too?