Bottom 5, 3 or 6, not much of a difference = is doing bad, will likely end, unless it's lucky and happen on the time others end.
You keep talking about 3 weeks before release, but do you have proof for that? Because as far I have noticed, they usually have only like 2 chapters in advance (whatever some mangaka have mentioned they are working on XX chapter). So more like they are printing 2 weeks before release. And content in the issue may be decide even if you want 3 or 10 weeks before that, doesn't mean the position in the toc is decided 3 weeks before that, it can easily be decided 1-2 days before printing.
Poll results have always mattered for them, and the way you are going means that they decided some of the series will do bad before even getting poll results (like Tokyo Wonder Boys and if that's the case, why did they even started it? Or Chagecha getting cancelled on 8th chapter?). So don't try making it like they do 7th chapter ToC before receiving the results of the 1st chapter. Also the whole 8 week rule is not set in stone, it's not like they came out and said it's like that. Not to mention the editor can always put a series up or down, no matter the poll results.
Unless you provide solid proof for the 3 weeks ToC position in advance, I will not be answering anymore. I don't see a reason to argue about speculative stuff and unconfirmed 8 week rule. Like I said the things I have heard is that they have around 2 chapters and they print around 2 weeks (except maybe during or upcoming holidays, printing even earlier will mean they will need more storage as they send out things around less than a week before release). I may have heard wrong, but it makes far more sense than what you are saying.
