No, you don't need homogeneity of thought and opinion. There's an obvious difference between holding an opinion and taking an action. Thinking it would be best for a group to fail and actively trying to make said group fail are two different things. Furthermore, the value of different thoughts and opinions is in the difference of approach and perspective, not necessarily in the thoughts or opinions themselves. The value comes from the act of consideration of other opinions and thoughts, not from blindly doing whatever other people (who may happen to disagree with you) want.
