Do we? In your dreams, you typically have access to more information than you do in waking hours... The zapping out of the real world, etc. all can be part of a hallucination.
That being said, I think there is a plot related reason which might blow the theory out of the water, which I think is what you are alluding to: There is more going on in Erfworld, apparently, than is necessary for the battle itself.
1) What is the relationship between Wanda, Ansom, and Jillian?
2) Where did Stanley come from, and why are his casters so loyal to him?
Now there may be simple answers which haven't been revealed, but I think the fact that those questions are interwoven in the narrative speaks to Erfworld having "a life of it's own."
Well observed.