The problem is this objection assumes there's never a clear-cut consensuses; we aren't usually talking here about questions with five different answers for five different people; we're often talking about two, and its not exactly hard for five people to decide between two options (assuming neither no one wants to decide, or its not so self-evident no one needs to decide)
Now, you can have a situation potentially where five different people strongly want different things in terms of basic campaign issues--but there's good reason to question whether they should be playing together in the first place.
(This is why I keep repeating that discussing how easy it is to make rules decisions collectively and campaign decisions collectively is not as useful as it could be because they're not really the same question.)