Ok i'm pretty sure the following advice should be across the board (someone correct me if it isn't). You should NOT be using the other set texts of physical journeys as related texts for your own physical journeys focus.
For one the markers won't even know which one was your prescribed text and which one was your supplementary. Also you'd definitely be 'double dipping' so to speak as there are a vast amount of resources for both these texts when really you should be showcasing your research/wide reading skills through your selection of texts.
I've heard that it's ok if you use a set text for one module and then transfer that over to another (i.e. using The Truman Show which is prescribed for some module in standard as an advanced module c telling the truth related) but ALSO only if you can demonstrate research/analysis that is more detailed and different than what was required for the previous module.