The key to everything in Dramatica—and therefore, in all things story—is to separate out the Main Character, Influence Character, and Relationship Story Throughlines from the Overall Story Throughline.
If the relationship covered in the Relationship Story Throughline is the very same relationship the Main and Influence Characters have in the Overall Story Throughline, then you haven't created a Relationship Story Throughline If the issues your Main Character suffers also find themselves showing up in the Overall Story Throughline or the Relationship Story Throughline, then you haven't built an effective Main Character Throughline
Ben and Luke have a mentor/mentee relationship outside of their relationship as fellow Rebels in the greater war. Max Durocher (Jamie Foxx) and Vincent (Tom Cruise) in Collateral have a friendship and similar mentor/mentee relationship outside of their relationship as captor and hostage in the struggle to stop the assassin wrecking havoc in Los Angeles.
Red (Morgan Freeman) has justifications for why he prefers to think like an institutionalized man in The Shawshank Redemption but his friendship with Andy centers around the made-up word hope. Newt in Aliens (Carrie Henn Danielle Edmond) spooks everyone out with her tales of monsters hidden in the dark, yet her relationship with Ripley (Sigourney Weaver) deals with the needs of mother and daughter.
The key to creating a robust story is to find the differences between the Throughlines…only to weave them back together into one seamless whole.