if there's a user with username:name
how to make him a sudo user without adding him to wheel group(intention is if wheel group is deleted)?
Add that user directly to /etc/sudoers or add a group to sudoers that the user is also in. Most distros use the commend visudo to edit this file.
Add that user, preferably at the bottom of the file under your own comment like:
#Admins username ALL=(ALL) ALL
or I like create an admin group like this:
User_Alias ROOTUSERS = jpratt ROOTUSERS ALL=(ALL) ALL