It's likely their digital circus form is related to their traumas/background.

>Posted youtube videos but no one watched them and that made her sad
>Is a Jester (entertainer)

>Had an overbearing mother and became a being that exist solely as a people-pleaser
>Is a literal doll

>Worked as a tattoo artist and a bartender, doesn't know her place in life and has an attitude
>Is a mix of random parts that have no order.

>Is the creator of the digital circus world/Caine AI
>Is a king.

>Is the wife of the creator of the digital circus/wife of the king.
>Is a queen.

>Wanted to be a mangaka, abandoned her dreams and went to work in a different thing she hates.
>Is a shell of a person that wears a mask of happiness that constantly breaks, leaving only sadness.

>Wanted to be a comedian, but his jokes suck
>Is a sad clown.

It might be a stretch, specially the Zooble Kinger ones. We know that kinger has a wife and that there is a queen that abstracted, i think it's fair to say they are the same.