I'm fairly certain that there is an error in this explanation.
For example, the following line from the /etc/sudoers file enables sudo access for members of group wheel.
%wheel ALL=(ALL) ALL
In this line, %wheel is the user or group to whom the rule applies. A % specifies that this is a group, group wheel. The ALL=(ALL) specifies that on any host that might have this file, wheel can run any command. The final ALL specifies that wheel can run those commands as any user on the system.
From my understanding, it has the explanation of (ALL) and the final ALL backwards.
(ALL) is in the position to define the "run as" what user [or group], with (ALL) meaning any user [or group].
The final ALL defines the command that the rule applies to.
Program Lead at Arizona's first Red Hat Academy, est. 2005 Estrella Mountain Community College