Quandry

When reading through my outline, I have a nice "Search for the McGuffin" adventure story. Under that is (what I hope will be) a subtle growth arc contrasting Family & Cultural Identity vs Self-Selected Identity (External vs Internal Validation).

There are scenes that provide forward motion for each plotline and some that hit both at the same time. I know the way I presented them the Growth arc seems like just a Theme, but in context it feels like plot.

My confusion comes in when trying to nail The Sentence. Should I have two Sentences?
How about doing the Amazon River? One is certainly fantasy/alternate history, the other is more literary. Which do I emphasize?

I have more pondering to do.