Okay, so the central tension in a lot of lycan king/fated mate plots hinges on this exact balance. The mate, especially a dire wolf, often isn't just a consort; she's a co-ruler with her own inherent power that can challenge or complement the king's authority. I see the loyalty part stemming from the fated bond itself—it's this primal, undeniable pull. But power? That's where the story gets juicy.
A well-written balance happens when her loyalty isn't blind obedience. It's loyalty to the pack, to their shared vision, not just to him as an individual. Her dire wolf nature might make her more attuned to the land or the ancient magic, giving her a type of authority he can't access. She balances his political cunning with raw, instinctual strength. The king has to respect that power, not just possess it, or the bond weakens. I think of it like a checks-and-balances system wrapped in a supernatural romance.
Books where the mate is immediately submissive miss the point. The real conflict—and the satisfying resolution—comes when she uses her power to protect him from himself sometimes, or to make a brutal call he's too entrenched to see. Her loyalty is proven when she stands beside him, not behind him, during a challenge.