As I recall, it is possible for you to be in more than one group; for instance,
at home, I'm in something like 8 groups.  Typically, sysadmins are added to
group wheel.

In some variants, if no one at all is in group wheel, anyone is allowed to su.

I don't always like the non-wheel can't su policy, so it's nice to be able to
turn it off, but I don't think it's a fascist thing.  Precisely how does one
define 'unwarranted' power of a legitimate root user?  If you have a legit
reason to have root privs, IMHO, you have legitimate authority to do anything
on the machine... After all, people who don't like your policies can just get
their own.

-s