Risen skin line and GOTS skin line, what is their relation?

Greetings,

I was curious if anyone who may have a little more extensive knowledge of the Shurima lore could inform me of the relation between the Risen skin line and the Guardian's of the Sands skin line, and if you could confirm that it is a separate skin line and also the counter part to the GOTS line, I'm really interested to learn a bit more cause I love the GOTS line but don't know as much as I'd like to about the Shurima lore, thanks!