I was never told that JW's were expected to believe the same thing.
They never told me that either, or I wouldn't have joined. There is a lot they don't tell you when you study. Even after being baptised for years, there is a lot you aren't told. They misrepresent and withhold information, and if you challenge them, then they come down on you with all this stuff, and you're like, WTF? I've been in 15 years and didn't know they can take my family away from me for not believing xyz?!
This religion bears most of the hallmarks of a cult.