De acordo com a página de manual :
sudo allows a permitted user to execute a command as the superuser or another user, as specified by the security policy.
[...]
When sudo executes a command, the security policy specifies the execution environment for the command. Typically, the real and effective user and group and IDs are set to match those of the target user, as specified in the password database, and the group vector is initialized based on the group database (unless the -P option was specified).
The following parameters may be specified by security policy:
- real and effective user ID
- real and effective group ID
- supplementary group IDs
- the environment list
- current working directory
- file creation mode mask (umask)
- SELinux role and type
- Solaris project
- Solaris privileges
- BSD login class
- scheduling priority (aka nice value)
Para responder à sua pergunta, alterar as IDs de usuário e grupo efetivas de um processo é apenas uma maneira de alterar os privilégios de um processo, a política de segurança definida em sudo.conf pode usar qualquer outro tipo de parâmetro na lista acima.