Crusoe and Friday's relationship is different in many ways to Attean and Matt's.  For example, Crusoe saved Friday by shooting the wildman and Attean saved Matt by getting him out of the water.  Matt taught Attean how to read and Attean got food for them in exchange. Another difference is that Friday dies in the story of  Robinson Crusoe and Attean doesn't die. Those are some differences between the relationships of Crusoe and Friday and Attean and Matt.