There should be an infinite number that meet that criteria if they had access to an infinite number of universes.
So while the setting might imply they have an infinite number of ACTUAL universes, they only have access to a finite number.
There was a very brief blurb in one of the episodes at the council of ricks where they mention the "central finite curve".
Chances are there is something that limits the access they have to a certain "group" that has something connecting them. Its all loose pseudoscience, but all signs in the show point to the fact that they don't have access to an actual infinite number of universes.