I asked this question and it seems there divisional applications can have the same detailed description.
I know that before the patent is issued, I can file another application claim priority date of the first application, e.g. continuation or divisional.
What I am trying to do is filing a application with multiple unrelated inventions (see the image below). I will pursue an invention but repeat the whole detailed description about multiple invention. While I pursue one invention, I will try to find commercial potential of other inventions. If another invention has commercial potential, I will file continuation application about it. It seems this will be perfectly legal.
As an independent inventor, I hope that strategy will reduce cost, as I only pursue just one invention instead of pursuing multiple ones at the same time. But in practice, they are unrelated inventions, so can I file continuation application like that?