Job well done!
I'm I the only one around here that doesn't give a damm about their sizes?! (those navels though)
Nice fanart, btw. I would've put Ruby on the front and so on, but your composition is fine, none the less. I really like how you put all the four colors in the backgroung, very nice touch. Also, unless you want Yang to punch you into a fiery pulp of human flesh, I'd add the little fleck of hair on top of her head. Just saying.
... So it's going by breast size, right?
P.S. YANG FTW!!