>> those who "challenge the book" instead of "follow the book"
This is a valid position and one I can identify with personally, but as I've gotten more emotionally mature over time find it's a little more subtle. You need to include your risk propensity and methodology into the calculation. Even within established companies roles, teams and individual situations are going to be vastly different. Are you willing to take bet-your-career risks? Have you earned some shared vulnerability with the people you want to change? Do you truly care about them and your company? I've learned these are all necessary if not sufficient regardless of the corporate landscape.
I believe there is a third way where you work within the system to affect meaningful change (or bring it down from the inside, depending on how radical your viewpoint). I've come to the realization that small minorities want either dramatic change or none at all; the vast majority are just apathetic, which is your biggest enemy. Start-ups likely skew towards the big change camp. You can make a difference in the former environment but it is exhausting and risks turning you apathetic as well.