As others have said, main problem is: I don't actually like the knight-captain. He's like the second-most-unlikable guy in the vicinity. Full of smarm, and distinctly too old for her (perhaps not, it should be said, for her somewhat ambiguous mental age; but him responding positively to any of her advances without that getting addressed first would be so creepy).
Lutz is adorable and he looks the best with the Princess, I ship. And I agree, there's no need to go the oldest dude's route, there are many better alternatives! >n<