There was a lady who wrote a comment under this article whose experience didn't match what I wrote, so maybe you also aren't able to relate.
But in my experience, if two people with codependent traits get together, they aren't one in the same. Someone is more codependent than the other, meaning the other would be more narcissistic. It's like a scale where on the left would be a codependent and on the right the narcissist.
If we were talking about someone with acute codependency I can't see how they'd ever get with another codependent. They'd naturally end up with someone with legit narcissistic personality disorder.
Most people have codependent traits but again in my experience, the codependent-narcissistic dance still plays out. It all depends on who is more codependent or narcissistic.
Hope this helps!