#4 Ronda Rousey

Believe it or not, Ronda Rousey won't last long in WWE.
While some might see that as an impossibility, especially with all the attention she is currently garnering for WWE, she apparently doesn't want to stay in the company past the two-year mark. Of course, that might change if WWE is able to offer her an easier schedule or more money, but according to multiple sources, she will call it a career after her first contract is up.
Again, this might sound crazy, but it becomes less crazy when you consider the acting roles that Rousey is starting to come in. Another thing that makes it a little less crazy is the amount of damage that Rousey and any other superstar do to their body during the course of a match, which might also be playing a role in the two-year decision.
In the end, it's not a huge loss and will at least give The former Bantamweight champion a chance to accomplish everything she ever dreamed of in WWE, but be ready to say goodbye when the time does come for her to retire!