IIRC, stripping out the Antergos bits is a pita; lots of outdated guides on the subject. Might as well install good ole Arch if that's the end goal anyway.
Simplest/fastest method I've found so far... ArcolinuxD..
Use that to get an easy, minimal CLI setup then install your D.E., I have KDE to just a few commands and only a few minutes total.
My older Ubuntu MATE VM is becoming a bit slow, so I'm investigating alternatives.
These are very fast/bare installs.
I do a base install, then after the reboot clone it before installing the desktop. Saves you from having to start from scratch each time.
KDE:Install with Arcolinuxd
restart
sudo systemctl disable lightdm.service
sudo pacman -S sddm plasma-meta (use defaults)
sudo systemctl enable sddm.service
sudo shutdown -r now (restarts the system)
Not sure why they enable lightdm (desktop manager) by default, it's not installed, but leaving this messes with sddm (desktop manager).
Mate:Install with Arcolinuxd
restart
sudo pacman -S lightdm-gtk-greeter-settings marco mate-extra (use defaults)
sudo systemctl enable lightdm.service
sudo shutdown -r now (restarts the system)
Vbox packages:sudo pacman -S linux-headers
sudo pacman -S virtualbox-guest-dkms
sudo pacman -S virtualbox-guest-utils
sudo systemctl enable vboxservice.service
restart
Note: you will need to enable bi-directional clipboard and such in the VM interface