PS:
Oops, I forgot to mention, that you might want to take a look at reverse dependencies of the gnome-things that are running.
Use
pactree -r package
I don't have GNOME installed, but I'm e.g. using Evolution:
[rocketmouse@archlinux ~]$ ps aux | grep /usr/lib/gnome | head -1 rocketm+ 840 0.0 0.3 751568 30648 ? Sl Jun23 0:00 /usr/lib/gnome-online-accounts/goa-daemon [rocketmouse@archlinux ~]$ pactree -r gnome-online-accounts | head -2 gnome-online-accounts ├─evolution-data-server
Some apps have got a hard dependency to software that actually should be an optional dependency, for example gvfs, that's why I build an empty dummy package, to fake that it is installed:
[rocketmouse@archlinux ~]$ pacman -Qi gvfs Name : gvfs Version : 2013.08.18-1 Description : Dummy package [snip] Required By : caja libgnome nautilus nemo Optional For : evince ffmpegthumbnailer inkscape thunar [snip]