Same artist?

I can't figure out if this is the same artist or not. Their sites are linked together, but their work seems to be different styles.

yukino_minato and tamago

These two websites link to their blogs:
http://www.noraneko-no-tama.com/
http://www.yotsumi423.com/

In the artist entry for Yukino Minato, they belong to the group "noraneko_no_tama". Should both artists just be added to this group and leave them separate?

It looks like the top site is the website for two different circles for some reason. tamago is a part of Yotsumi Works, which is located here. There's a link to that site on the noraneko main site.

• "Yotsumi works" is a general (non-ero) circle by Tamago, Suzuruu and Yigami.
• "Noraneko no Tama" is an ero circle by Yukino Minato and Chiba Chibasa.

According to their dojinshi data, they seem to have published both ero and non-ero dojinshi as "Yotsumi works" at first.