Responses

They were just teenagers before dying, highschoolers. And being an 18 yr old you're still not really exposed to manipulation in some manga and right after reincarnating they were abused for 5 whole years ever since they were born in another world, just so you know in a child's eyesight bigger people are scary no matter what even if they're actually adults.
Their mental knowledge were bound to change. Even one month is more than enough for an competent adult to completely just believe every single thing even if they're manipulated. I get your point though
Come their "23" why are they believing people so easily and not trusting their own eye's. They have been through life already, they can't tell malicious intent from being coddled and pampered by their family. Yes they were abused but they're not getting that same treatment in the palace. Come on they got manipulated by a actually baby.