Hina being an airhead that had no contact with filth of an outside world would make sense if she didn't travel for long time before reaching the city, they also traveled together with mom, but let's say out of civilization reach.
Sheltered or even introverted people are easily manipulated, with low self esteem ever worse so I'll give it a moment of belief.
Even though Nana knew there's someone impersonating the Red Baron, simply let Nana get snatched so easily... that's dumb as fuck.
Also, the numbers they're "wearing" seem like
the episode of The Orville or social media, where people are judged and hierarchy is about "likes".