Cimorene

It could be why, but it's not true that there are only so many ways to get them to interact. If you survey most fandoms of any variety - movie, television, science fiction or otherwise, rps, anime, comics - you find a pretty wide range of plot devices ranging from the clichéd to the completely wtf-inducing. Fandom doesn't lack for imagination, and a lack of canon precedent has never stopped it before.