did he stumble upon one of them and thought "this is the perfect person for my bad place, now all i need to do is find the ones who would make this work." or something like that, and if he did, who was it? probably Eleanor…idk

yeah, i can see that.

how did michael have exatcly this four people avaible to him? like are the architects supplied with a database of the people that will eventualy die and then choose from there, or are they already dead stored somewhere ready for use?