I haven’t read the novel so this isn’t a spoiler, it’s just what I think, but he’s not assigning the knights to protect her. He’s assigning them to keep her away from his retainers, the lesser Nobles in his domain, because he married her with the understanding with his retainers that once his curse was cured, and he no longer needed someone that could fight him during the night, that he would divorce her and marry one of their daughters or someone else that would give him a political marriage, a beneficial marriage. Since the land that she comes from is incredibly poor, she brings nothing to the table other than her ability with a sword, but he’s fallen in love with her at this point so he does not want her to ever leave. He’s not planning to divorce her, ever, and he’s worried that if she meets any of his retainers in the castle that they’ll belittle her and basically remind her that she’s temporary and put into her head that she is not going to be his wife forever and that she’s going to eventually have to leave and he’s worried that she’ll believe it and when the time comes, she’ll try to leave him because she thinks she has to or something and he’s terrified she’ll leave him to go back to her homeland, cause he doesn’t want that, he wants her to stay with him forever regardless of what she wants.

Does anyone have spoiler about what’s going on in the castle
Why is everyone acting weird and who does she need protection from ?