You need to get maximum possible points in the Elite Archimedea to get the Archimedean Eye Sumdali, yeah. So if you're getting the Vosphor tier for the first time, you're also getting the Sumdali.
I guess it's to encourage people to go above and beyond, much like with The Fragmented One (60 eyes assasination). There isn't much of a reward for it other than the sumdali and overcoming the challenge, I guess. At least it's one and done.
The Sumdali itself also inherits the colors of your Landing Craft, which is a blessing and a curse. Primary colors the metallic supports, secondary colors the cylinder holding the eye and some of the support ornamentation, and Tetriary colors the eye's sclera (The eye moves and looks around, by the way).
The problem is, if you have a tetriary color anything other than some kind of white, the eye gets a heavy tint, and looks like a dark glistening orb if you choose a dark color. So you don't even see the eye if you don't want a light Tetriary on your Landing Craft (looking at you, Scimitar). So I didn't even end up equipping mine because of this. Would've been nice if it was colored separately.