Looks random at a glance, doesn't it?
But it really isn't. You see, superhumans are essentially the same thing as super robots, the difference being that a super robot is much larger than a superhuman and has a little person in its head or something.
And a super robot is essentially the same thing as a kaiju (in Evangelion, for instance, the "robots" are not actually machines but clones of a giant monster creature, and yes, they did have little people in their heads) except with a tiny little human controlling it from somewhere, instead of being essentially a huge animal-plenty of kaiju are actually mechanical.
And kaiju aren't that different from Lovecraftian monster gods; the big difference is that Lovecraft's monsters vary more in size than most kaiju, and almost inevitably have egos and intellects as big as the universe itself (and, while many kaiju are short-lived, Lovecraft's monsters are all ancient and immortal).
And Lovecraftian monster gods are only different from superhumans in that superhumans are, well, human, and the Lovecraftian monster gods are not so much.
And superhumans and super robots are essentially-wait, I did that one already.
My point (obviously) is that the distinctions between them as fictional devices are largely arbitrary, and they tend not to hang out together seamlessly because of genre conventions which developed as part of traditional processes. It's hardly impossible for these things to interact, and in fact they periodically do so, usually with ease. The lines between them are pretty blurry ones, as not all "superhuman" characters are necessarily human, it isn't technically necessary for a kaiju to be dumb and a newly arisen mutant, Lovecraftian monster gods could easily be mechanical (I've never really seen such a treatment, but then, I haven't seen everything), and super robots-well, the only thing really necessary for something to be a super robot is a Superman/Hulk-like smash-everything-while-showing-off-invulnerability quality (and even that isn't directly necessary-show the enemies the robot defeats doing that, and the robot can obviously do that by extension).
So, yeah. They're all sides of an extremely bizarre multidimensional coin.