I disagree, I think their dynamic is very interesting because it's not typical.
I love both couples.
Both Nana and Luliam struggle with self-worth, but they cope with it in different ways, and now that they're together they lift each other up. But now that Nana can't use magic anymore her low self-esteem is gonna creep up on her again.
Tsubasa and Eldora started out as bickering business partners, but there's more to that. Eldora is actually kind and cares about the people around her, but since she's a big stinkin tsundere, she comes across as bossy as she tries to do everything by herself. Which annoys the heck out of Tsubasa because she wants to be relied upon.
I love both ships' dynamics, and I demand MORE!