I'd just like to confirm, but Patron Trolls are chosen from who they like, and not from numbers and birthday codes, right? There's a lot of people who I know keep on trying to convince me that it's based on birthday numbers and dates, or by the other way that determines the dream planet and character.

In the story the patron troll was the one the Beta kids talked to the most/got the most help from.

Fandom-wise, there are several ways to find a patron troll, all of which are fine.  There is no right way to pick a patron troll.