Hello Sam,
Yes, it seems that some packages in Fedora pulls down more dependencies than I would like; for instance removing the GNOME Desktop group (if it actually existed) should only remove everything GNOME-related stuff and only that, not whatever else on what it may depend. Conversely, one should be able to install X or Wayland separately - at least that's how I used with Arch and Gentoo albeit RHEL seems more close to Debian in this regard.
About the question I made, I think it is quite self-explanatory: there are groups for every-other Desktop Environment (even one for Window Managers) but there's none for GNOME Desktop. Of course I believe one could go and remove leftovers by hand, what I say is that's strange - just to say something - that there isn't a meta-group that takes care of that.
Regards.