@frubam i think you're supposed to read both side by side since there's some event happening in one that doesn't happens in the other, yet treated as if it's happening in that one.
i remember the one in batoto have chapters from both interspersed with each other so the chapters count practically doubled, but it's the "right" way to read it.
something along that line. i only managed to read halfway before batoto gone, all the while never noticed that it's from 2 different source until i see that i'm reading chapter 30-ish as chapter 70-ish.