Which perceiving function helps with understanding more complex plots?

I'm reading Crime and Punishment in English right now, and I thoroughly enjoy it. Something I've noticed is that those in my reading group tend to have a hard time understanding what is going on, like Raskolnikov's mother's letter and Marmeladov's story (the drunkard in Part One Ch. 2), which honestly surprises me. For me, what happened is very clear. Even if I don't remember most of the events, I understand the general gist of it.

I thought it was a coincidence, but recently I started reading a manga and noticed the same thing happening again. Like, I know this one character killed the enemies because that's what I see from the panels in the chapter, but I asked others who read the same manga and they said that they had no idea what happened. This is really confusing. Like, isn't it really obvious with the way the story is presented?

I was wondering which perceiving function helped the most in taking in this information and narrowing them down.