I can see some faint potential in this, but we need the examples to explain HOW the characters play off each other.
For example, and I'm using a game I recently played, Star Ocean 6 to be exact, to show off what I mean.
"Raymond Lawrence and Laeticia Aucerius the main male and female hero of Star Ocean 6. You can even pick one as the canon main character, which will cause the story focus more on events from their POV whenever there is a story fork where they must split up. Certain characters are only recruitable for each one on their respective player path and certain scenes are only viewable for each character. This means it's worth playing as each character once per playthrougth to see all the content glossed over or not available when playing as the other."
Basically, the trope should explain why the work having this trope in effect makes the work stand out as a result.