You did really well on the yellow keeping it consistent, but I dont think ur gonna go past 6 on these because there isnt much to talk about.
One suggestion I would say that could help with getting higher scores and really woudlnt take anytime painting, would be adding more to the eye color, letting the joints be black or metalic, it makes there legs look like 1 solid piece instead of moveable parts, and perhaps adding a lil more metal to the faces, like in the breating mask and the cables.
Just some thoughts, not trying to bash just tryin to help.