No, it is a bit more complicated than that, but not too much.
I haven’t tested this but I think it would be something closer to this:
sudo pacman -Syu
sudo pacman -Rcsn gnome gnome-extras
sudo pacman -S networkmanager
sudo pacman -S plasma dolphin konsole
sudo systemctl enable sddm.service --force
I am not sure what the state of your network will be after removing and reinstalling networkmanager. You might have to start/restart the service in there.
Make sure you have a copy of the networkmanager package in your cache. If not, download it before you start.
Also, this is a pretty minimal kde install. You will probably want to add applications to suit your preferences after that.