The above the fold part of each doesn’t give enough info to make any kind of decision.
The above the fold part for coreos gives the impression you would use it for containers. Not a host for containers.
Above the fold - Cloud says it is for VMs, but so does server. ‘Lightweight vm’ vs ‘baremetal or vm’.
Cloud doesn’t have a ‘learn more’. It has 'documentation, which takes you to the rtd page which doesn’t really help tell you how it is different from the other options.
For coreos you click documentation and it takes you to the docs which don’t tell you what it is for whatsoever.
Cloud is optimized for running on cloud systems, e.g lightweight and on demand resource allocation. Server is optimized for installation directly on hardware or on virtualized hardware, characterized among other things by static resource allocation and long-term running.
Could that be on the pages themselves?
It sounds like cloud doesn’t have a reason to exist, since server sounds like the exact same thing but with an installer. It would probably be better to add it as a download option for server and call it ‘minimal qcow image’ or something. Wait that already exists Fedora Server | The Fedora Project
So what differentiates iot and coreos?
What additional information do you think would be helpful without being overloaded or how could the existing information get improved?
If it requires being ‘overloaded’ to explain the difference or use cases then perhaps that means they don’t need to be district distros. 
I love fedora and I’ve used it for almost 10 years. But starting a new home project and trying to pick which distro of fedora to use is way too much of a hassle. Too many similar options → choice paralysis. Choice paralysis is an undesirable feeling. Once paralyzed it is feel better to just choose something besides Fedora that is more clear with less choices!
It feels unpleasant enough I figured I had to bring it up. Who knows how many other people have been turned off Fedora because of this?
In addition by saying ‘This distro is for x’ you are implicitly stating the other distros (re server) is not for x. Which hurts your branding as well.