To add a new sudo user I believe I can call:
# to create a new user sudo adduser newusername
and to allow this user to use sudo I can do:
sudo adduser newusername sudo
sudo gpasswd -a newusername sudo
If this is correct, is there any difference between these commands or reasons to use one over the other for primarily Ubuntu server hardening script, but also trying to be as generic as possible, eg different Linux versions or distribution compatibility?