I don't know why the author was so worried about the question of "What about the kids that were absent during the event?". In doing so, he created a few more issues and questions. He didn't need to do this at all since collecting people outside of the school zone format is much harder to pull off. They don't need to be talked about or mentioned as we as readers can just assume they were just "lucky" and didn't have to undergo these trials. And the method on how to contact the kids seem very stupid and would cause a good deal of problems. Really, just spamming the door bell? How drastic would those Ninomiya Sontoku's go to get into contact with those kids. Would they have to kill a large number of parents to do so? And was to reject the offer normally dealt with by death? If not, then why did so many kid actually decide to partake in the trials even after knowing how high the death rate was from the news?

This authors execution is getting really really sloppy. Even in the character development. Besides the 2 main soccer players, those kids introduced in the garbage can academy are utterly bland and thoughtless unlike those in the original series. Ushimitsu Kyoshirou is a good example of poor execution. Even the current antagonists are now blabbing too much. They're taking away from the aesthetics that was carefully brought up with those unique mysterious villains that were presented in the original series.

Read up to chapter 9 and I'm worried for this series...

I know this post to this topic is late but don't give up hope! I agree that it took a while for the author to start up but by the first task the "garbage" students (aka the students that didn't go to school) it starts to have that similar vibe of the first publication. By chapter 15 Hopefully the author will make this series as good as the first one.