Star is from a different dimension.
Stan’s brother was lost in a different dimension.
Rick visits different dimensions like twice a week.
Lot of dimension shenanigans goin on these days.
You know, technically, they can share one story. because of themultiverse being canon in all of them. And rick and morty DOES take place in one of the universes that stanley scanned. The mystery shack mug came through a portal in rick and morty that one time.