Here is a more complete view of how I am using this.
We use the Remove feature to trim down the Music, AppleTV, PodCasts, etc apps.
USERNAME=$(/bin/ls -l /dev/console | /usr/bin/awk '{ print $3 }')
dockutil="/usr/local/bin/dockutil"
#remove stuff
sudo -u $USERNAME $dockutil --remove all --no-restart --allhomes
#add stuff
sudo -u $USERNAME $dockutil --add '/System/Applications/Launchpad.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Self Service.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Google Chrome.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Microsoft Excel.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Microsoft Word.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Microsoft PowerPoint.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Slack.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/zoom.us.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/System/Applications/System Settings.app' --no-restart --allhomes
#add folders
sudo -u $USERNAME $dockutil --add '/Applications/' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '~/Downloads/' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '~/Documents/' --no-restart --allhomes
#kill Dock
sudo killall Dock