What determines opposites?
If a man who is 5'2" and a woman who is 6'4" get together, you'd think that they are opposites. He might be from Minnesota and she from Texas, and we'd all call them opposites. But they might have similiar interests, jobs, hobbies and personalities. So for the few things that they have that are opposite, they have many things that are similiar.
Or what about the picture perfect couple that appears to have everything in common: looks, families, goals, careers, yet they differ drastically in personality. So similiar, yet so opposite.
I think that for every couple, there are similiarities and differences. I have never seen two people exactly alike.